test-convert: disable autocrlf for git

Git might have autocrlf=true as a global or default setting, especially on
windows. That is not expected in the tests and can cause
+  warning: LF will be replaced by CRLF in d/b.
+  The file will have its original line endings in your working directory.

Explicitly setting it false will make the test pass in some setups - but still
not out of the box.

tests/test-convert-git.t

@@ -1,5 +1,7 b''
 
   $ "$TESTDIR/hghave" git || exit 80
+  $ echo "[core]" >> $HOME/.gitconfig
+  $ echo "autocrlf = false" >> $HOME/.gitconfig
   $ echo "[extensions]" >> $HGRCPATH
   $ echo "convert=" >> $HGRCPATH
   $ echo 'hgext.graphlog =' >> $HGRCPATH

tests/test-convert-tagsbranch-topology.t

@@ -1,5 +1,7 b''
 
   $ "$TESTDIR/hghave" git || exit 80
+  $ echo "[core]" >> $HOME/.gitconfig
+  $ echo "autocrlf = false" >> $HOME/.gitconfig
   $ echo "[extensions]" >> $HGRCPATH
   $ echo "convert=" >> $HGRCPATH
   $ echo 'hgext.graphlog =' >> $HGRCPATH