Add missing :leave-mode for insert-mode test

Otherwise we hint while still in insert mode - while this seems to work
fine, let's do things the cleaner way.

tests/end2end/test_insert_mode.py

@@ -57,6 +57,7 @@ def test_insert_mode(file_name, elem_id, source, input_text, auto_insert,
         quteproc.send_cmd(':debug-set-fake-clipboard "{}"'.format(input_text))
         quteproc.send_cmd(':insert-text {clipboard}')
 
+    quteproc.send_cmd(':leave-mode')
     quteproc.send_cmd(':hint all')
     quteproc.wait_for(message='hints: *')
     quteproc.send_cmd(':follow-hint a')