Post-nonexistent-revision crash sidestepped

Fix for the bug that leaves a fractional .git directory after attempting to
perform an initial sync to a nonexistent revision. Moved the initialization of
the working directory to after the revision ID has already been checked. Now,
no project/.git directory gets created at all if the revision ID is bad.

Change-Id: I0c9b2a59573410f1d11de7661591bf02e4ce326b
1 file changed