Merge branch 'rf/completion-config-commit' into maint

Completion update.

* rf/completion-config-commit:
  completion: add completions for git config commit

Author: gitster

contrib/completion/git-completion.bash

@@ -2392,8 +2392,11 @@ _git_config ()
 		color.status.untracked
 		color.status.updated
 		color.ui
+		commit.cleanup
+		commit.gpgSign
 		commit.status
 		commit.template
+		commit.verbose
 		core.abbrev
 		core.askpass
 		core.attributesfile