Fix crash with domain_aliases for ADFS

[jscannell]

Description

When setting domain_aliases on an ADFS connection the following crash occurs:

Stack trace from the terraform-provider-auth0_v0.30.3.exe plugin:

panic: interface conversion: interface {} is *schema.Set, not []interface {}

goroutine 16 [running]:
github.com/auth0/terraform-provider-auth0/auth0.Slice({0xcb4b10, 0xc000582560}, {0xb89507, 0xe}, {0x0, 0x0, 0x0})
github.com/auth0/terraform-provider-auth0/auth0/resource_data.go:286 +0xe5
github.com/auth0/terraform-provider-auth0/auth0.expandConnectionOptionsADFS({0xcb4b10, 0xc000582560})
github.com/auth0/terraform-provider-auth0/auth0/structure_auth0_connection.go:796 +0x85
github.com/auth0/terraform-provider-auth0/auth0.expandConnection.func1({0xcb4b10, 0xc000582560})
github.com/auth0/terraform-provider-auth0/auth0/structure_auth0_connection.go:435 +0x19f
github.com/auth0/terraform-provider-auth0/auth0.(*list).Elem(0xc00058b530, 0xc000582540)
github.com/auth0/terraform-provider-auth0/auth0/resource_data.go:345 +0x43
github.com/auth0/terraform-provider-auth0/auth0.expandConnection({0xcb4bb0, 0xc0002bb480})
github.com/auth0/terraform-provider-auth0/auth0/structure_auth0_connection.go:398 +0x53b
github.com/auth0/terraform-provider-auth0/auth0.updateConnection({0xcb2ab8, 0xc00007eae0}, 0xc0002bb480, {0xac8fc0?, 0xc00057a640?})
github.com/auth0/terraform-provider-auth0/auth0/resource_auth0_connection.go:825 +0x50
github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema.(*Resource).update(0xc0004b08c0, {0xcb2af0, 0xc000298840}, 0xd?, {0xac8fc0, 0xc00057a640})
github.com/hashicorp/terraform-plugin-sdk/[email protected]/helper/schema/resource.go:741 +0x12e
github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema.(*Resource).Apply(0xc0004b08c0, {0xcb2af0, 0xc000298840}, 0xc0000451e0, 0xc0002ba280, {0xac8fc0, 0xc00057a640})
github.com/hashicorp/terraform-plugin-sdk/[email protected]/helper/schema/resource.go:847 +0x82c
github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema.(*GRPCProviderServer).ApplyResourceChange(0xc0004865e8, {0xcb2a48?, 0xc00025f280?}, 0xc000324320)
github.com/hashicorp/terraform-plugin-sdk/[email protected]/helper/schema/grpc_provider.go:1021 +0xe3c
github.com/hashicorp/terraform-plugin-go/tfprotov5/tf5server.(*server).ApplyResourceChange(0xc00045ab40, {0xcb2af0?, 0xc000298030?}, 0xc000106000)
github.com/hashicorp/[email protected]/tfprotov5/tf5server/server.go:812 +0x515
github.com/hashicorp/terraform-plugin-go/tfprotov5/internal/tfplugin5._Provider_ApplyResourceChange_Handler({0xb50b00?, 0xc00045ab40}, {0xcb2af0, 0xc000298030}, 0xc00019aa20, 0x0)
github.com/hashicorp/[email protected]/tfprotov5/internal/tfplugin5/tfplugin5_grpc.pb.go:385 +0x170
google.golang.org/grpc.(*Server).processUnaryRPC(0xc0002b8a80, {0xcb5608, 0xc00051c1a0}, 0xc0000da480, 0xc0004e2ed0, 0x1191c60, 0x0)
google.golang.org/[email protected]/server.go:1283 +0xcfd
google.golang.org/grpc.(*Server).handleStream(0xc0002b8a80, {0xcb5608, 0xc00051c1a0}, 0xc0000da480, 0x0)
google.golang.org/[email protected]/server.go:1620 +0xa1b
google.golang.org/grpc.(*Server).serveStreams.func1.2()
google.golang.org/[email protected]/server.go:922 +0x98
created by google.golang.org/grpc.(*Server).serveStreams.func1
google.golang.org/[email protected]/server.go:920 +0x28a

Error: The terraform-provider-auth0_v0.30.3.exe plugin crashed!

This change fixes the crash by updating expandConnectionOptionsADFS to behave consistently with the other connection strategies.

Checklist

Note: Checklist required to be completed before a PR is considered to be reviewable.

Auth0 Code of Conduct

• I have read and agreed to the terms within the Auth0 Code of Conduct

Auth0 General Contribution Guidelines

• I have read the Auth0 General Contribution Guidelines

Changes include test coverage?

• Yes
• Not needed

Does the description provide the correct amount of context?

• Yes, the description provides enough context for the reviewer to understand what these changes accomplish

Have you updated the documentation?

• Yes, I've updated the appropriate docs
• Not needed

Is this code ready for production?

• Yes, all code changes are intentional and no debugging calls are left over

[sergiught]

Thanks for the contribution @jscannell !