Cannot switch and create a new branch in a colocated workspace

[Luis Arias]

This is with rev 466 of bzr explorer. To reproduce create a colocated workspace with colo-init. Then use the switch dialog (see attached screenshot) to switch and create a new branch. I get the following trace:

Run command: bzr switch --create-branch file:///home/luis/workspace/test-switch-and-create/.bzr/branches/trunk/
bzr: ERROR: File exists: u'/home/luis/workspace/test-switch-and-create/.bzr/branches/trunk/.bzr': [Errno 17] File exists: '/home/luis/workspace/test-switch-and-create/.bzr/branches/trunk/.bzr'

[Alexander Belchenko (bialix)]

As I can see explorer uses wrong branch name when trying to execute operation.

Workaround: use `colo:xxx` as branch name in the combolist instead of just `xxx`