Network spinner blocks custom RPC form

[danfinlay]

Story:

• User wants to connect to a custom RPC
• They enter the RPC wrong
• The spinner appears
• They click the network menu again to select custom again
• They are taken back to settings, but cannot edit the form:

This enhancement needs design first:
MetaMask/Design#21

[bdresser]

@danfinlay @cjeria when I put in a custom RPC, it adds that new URL to the list of networks.

If I click "Custom RPC" again, it feels like the extension should stop trying to connect to the previously entered URL, cancel the spinner, and drop me on a fresh settings page. (Right now it just continues to try connecting to the URL I entered)

Potentially a design-free solution?

[danfinlay]

Right now this bug doesn't exist on old-UI because it just doesn't show the spinner on the settings page, which has the same ultimate effect: People can pick a new custom RPC even when they were just searching for one. I like this solution because it's easier to implement, but either would be good.

[cjeria]

This sounds like a good opportunity to time-out with a message to "Try again" and link to the settings page per @bdresser suggestion. Easy enough to create a design for if this sounds like a desirable implementation.

[bdresser]

closing in favor of #3776