Fix one old occurence of gitflow_check_ -> gitflow_require_
diff --git a/git-flow-feature b/git-flow-feature
index 482b298..217245c 100644
--- a/git-flow-feature
+++ b/git-flow-feature
@@ -190,7 +190,7 @@
 helper_finish_cleanup() {
 	# sanity checks
 	gitflow_require_branch $BRANCH
-	gitflow_check_clean_working_tree
+	gitflow_require_clean_working_tree
 
 	# delete branch
 	git push $ORIGIN :refs/heads/$BRANCH