fix dm custom slash command regression (#7008)

webapp/components/create_comment.jsx

@@ -10,6 +10,7 @@ import UserStore from 'stores/user_store.jsx';
 import PostDeletedModal from './post_deleted_modal.jsx';
 import PostStore from 'stores/post_store.jsx';
 import PreferenceStore from 'stores/preference_store.jsx';
+import TeamStore from 'stores/team_store.jsx';
 import MessageHistoryStore from 'stores/message_history_store.jsx';
 import Textbox from './textbox.jsx';
 import MsgTyping from './msg_typing.jsx';
@@ -199,6 +200,7 @@ export default class CreateComment extends React.Component {
 
         const args = {};
         args.channel_id = this.props.channelId;
+        args.team_id = TeamStore.getCurrentId();
         args.root_id = this.props.rootId;
         args.parent_id = this.props.rootId;
         ChannelActions.executeCommand(