Fetch Branch dialog: Local branch name still claims to be required when field is insensitive

[Dylan McCall]

In the dialog titled Select Branch (which opens when fetching a bzr branch), there is a text box at the bottom with a loud label that says "*Required* Local branch name:"

This is all fine and dandy in one case, where the "Make local changes" retrieval type is selected. In the two other cases, the text box is insensitive but the label still loudly says it's required. This could frighten some users :)

[Martin Owens (doctormo)]

All fixed