Remove broken link that 404s and has no alternative

doc/update/6.x-or-7.x-to-7.14.md

@@ -20,7 +20,7 @@ database migrations for GitLab 7.2.
 
 ## Stash changes
 
-If you [deleted the vendors folder during your original installation](https://github.com/gitlabhq/gitlabhq/issues/4883#issuecomment-31108431), [you will get an error](https://gitlab.com/gitlab-org/gitlab-ce/issues/1494) when you attempt to rebuild the assets in step 7. To avoid this, stash the changes in your GitLab working copy before starting:
+If you deleted the vendors folder during your original installation, [you will get an error](https://gitlab.com/gitlab-org/gitlab-ce/issues/1494) when you attempt to rebuild the assets in step 7. To avoid this, stash the changes in your GitLab working copy before starting:
 
     git stash