clone: add a period after "done" to end the sentence

We have a period in other places after "done" (see e.g. clone_local), so
we should have one here, too.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

builtin/clone.c

@@ -556,7 +556,7 @@ static void update_remote_refs(const struct ref *refs,
 							      0, &rm, transport))
 			die(_("remote did not send all necessary objects"));
 		if (0 <= option_verbosity)
-			printf(_("done\n"));
+			printf(_("done.\n"));
 	}
 
 	if (refs) {