completion: git commit should list --interactive

Signed-off-by: Eric Raible <raible@gmail.com>
Acked-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -750,7 +750,7 @@ _git_commit ()
 	--*)
 		__gitcomp "
 			--all --author= --signoff --verify --no-verify
-			--edit --amend --include --only
+			--edit --amend --include --only --interactive
 			"
 		return
 	esac