message: Escape single quotes in composer placeholder
diff: @@ -219,7 +219,9 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
  };
  private showPlaceholder() {
  - this.editorRef.current.style.setProperty("--placeholder", `'${this.props.placeholder}'`);
  + // escape single quotes
  + const placeholder = this.props.placeholder.replace(/'/g, '\\\'');
  + this.editorRef.current.style.setProperty("--placeholder", `'${placeholder}'`);
  this.editorRef.current.classList.add("mx_BasicMessageComposer_inputEmpty");
  }
  