repo: Remove another usage of bare 'except'

Change-Id: I9195b40f5af7cbf74b47376a4708de82495f8fba
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254696
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: David Pursehouse <dpursehouse@collab.net>

repo

@@ -597,7 +597,7 @@ def _InitHttp():
       p = n.hosts[host]
       mgr.add_password(p[1], 'http://%s/' % host, p[0], p[2])
       mgr.add_password(p[1], 'https://%s/' % host, p[0], p[2])
-  except:
+  except Exception:
     pass
   handlers.append(urllib.request.HTTPBasicAuthHandler(mgr))
   handlers.append(urllib.request.HTTPDigestAuthHandler(mgr))