"Team or User Account:" is not validated properly

When adding a new Bitbucket account in the connector, the field "Team or User Account:" isn't validated properly and can throw the user a stack trace. To reproduce, do the following:

Add a New Account with the following

• • Team or User Account: - Something completely invalid, like a misspelled user/team name
  • Admin Username: - Your correct username
  • Admin Password: - Your correct password
  • Auto Link New Repositories: - Checked

When you make the connection, it will stack trace instead of providing useful feedback (ie. a 404). Furthermore, it will create the connection anyway, with the invalid name as a linked heading with no repositories.