hgit: make sure repository is local before checking for store type

httppeer (and maybe others too) does not have a store attribute. This was
causing `hg pull` being broken on a hg repository when the extension is enabled.

localpeer.local() does returns a non-None value but I am not sure if it matters.

Differential Revision: https://phab.mercurial-scm.org/D8217

hgext/git/__init__.py

@@ -230,7 +230,7 b" def init(orig, ui, dest=b'.', **opts):"
 
 
 def reposetup(ui, repo):
-    if isinstance(repo.store, gitstore):
+    if repo.local() and isinstance(repo.store, gitstore):
         orig = repo.__class__
         repo.store._progress_factory = repo.ui.makeprogress