Track RT mode once we've retrieved the setting from account data

src/components/views/rooms/MessageComposerInput.js

@@ -161,6 +161,8 @@ export default class MessageComposerInput extends React.Component {
 
         const isRichtextEnabled = UserSettingsStore.getSyncedSetting('MessageComposerInput.isRichTextEnabled', false);
 
+        Analytics.setRichtextMode(isRichtextEnabled);
+
         this.state = {
             // whether we're in rich text or markdown mode
             isRichtextEnabled,