message: Move cursor to end of editor when quoting
  When quoting a message, move the selection to the end of the input box. Fixes
diff: @@ -229,7 +229,8 @@ export default class MessageComposerInput extends React.Component {
  if (this.state.isRichtextEnabled) {
  contentState = Modifier.setBlockType(contentState, startSelection, 'blockquote');
  }
  - const editorState = EditorState.push(this.state.editorState, contentState, 'insert-characters');
  + let editorState = EditorState.push(this.state.editorState, contentState, 'insert-characters');
  + editorState = EditorState.moveSelectionToEnd(editorState);
  this.onEditorContentChanged(editorState);
  editor.focus();
  }
  