message: rte: special return handling for some block types
diff: @@ -513,11 +513,18 @@ export default class MessageComposerInput extends React.Component {
  };
  handleReturn = (ev) => {
  + const currentBlockType = RichUtils.getCurrentBlockType(this.state.editorState);
  + // If we're in any of these three types of blocks, shift enter should insert soft newlines
  + // And just enter should end the block
  + if(['blockquote', 'unordered-list-item', 'ordered-list-item'].includes(currentBlockType)) {
  if(ev.shiftKey) {
  this.onEditorContentChanged(RichUtils.insertSoftNewline(this.state.editorState));
  return true;
  }
  + return false;
  + }
  +
  const contentState = this.state.editorState.getCurrentContent();
  if (!contentState.hasText()) {
  return true;
  