test-convert-git: drop a git warning that doesn't occur on Windows
I do see this on Linux with 1.7.7.6, but not on Windows with 1.9.5.msysgit.0.
Adding a (?) didn't work to conditionally ignore the line; I'm not sure if the
(glob) interferes with that.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..