Fix git call

commander/gui/zapper.py

@@ -126,7 +126,7 @@ class GlobalZapper(QObject):
             if path.suffix != ".ipynb":
                 continue
 
-            nb_commit = git.git_stdout("rev-list", "-1", branch, "--", name)
+            nb_commit = git.REPO.git_stdout("rev-list", "-1", branch, "--", name)
             yield FileInfo(commit=nb_commit, path=path)
 
     def _validate_notebook_path(