Revert "Merge branch 'git-pull-fix-hang' into 'master'"

This reverts merge request !241

Makefile

@@ -109,7 +109,7 @@ gitlab/.git/pull:
 	cd ${gitlab_development_root}/gitlab && \
 		git checkout -- Gemfile.lock db/schema.rb && \
 		git stash && git checkout master && \
-		git pull --ff-only upstream master
+		git pull --ff-only
 gitlab-shell/.git/pull:
 	cd ${gitlab_development_root}/gitlab-shell && \