Make test-convert-git compatible with other git versions (tested with 1.4.4.3)

tests/test-convert-git

@@ -7,12 +7,12 b' echo "convert=" >> $HGRCPATH'
 
 mkdir git-repo
 cd git-repo
-git init
+git init-db >/dev/null 2>/dev/null
 echo a > a
 git add a
-git commit -m t1 > /dev/null || echo "git commit error"
+git commit -m t1 >/dev/null 2>/dev/null || echo "git commit error"
 echo b >> a
-git commit -a -m t2 > /dev/null || echo "git commit error"
+git commit -a -m t2 >/dev/null || echo "git commit error"
 cd ..
 
 hg convert git-repo

tests/test-convert-git.out

@@ -1,4 +1,3 b''
-Initialized empty Git repository in .git/
 assuming destination git-repo-hg
 initializing destination git-repo-hg repository
 scanning source...