GrpcService is not compatible with grpc server running on the same port as http

[fedinskiy]

When Quarkus run with GRPC, it complains about legacy GRPC support and recommends to disable a separate server with an option: quarkus.grpc.server.use-separate-server=false. If the option is added, grpc is accessible on the same port as http, ie it is described by variable quarkus.http.port and not by quarkus.grpc.server.port. Unfortunately, in such case our GRPC service still tries to access grpc port (eg: [1]) and fails.

[1] https://github.com/quarkus-qe/quarkus-test-framework/blob/main/quarkus-test-core/src/main/java/io/quarkus/test/services/quarkus/LocalhostQuarkusApplicationManagedResource.java#L101-L103