message: Fix invalid commands when figuring out whether to send typing notification
diff: @@ -170,7 +170,7 @@ export default class BasicMessageEditor extends React.Component {
  // If the user is entering a command, only consider them typing if it is one which sends a message into the room
  if (isTyping && this.props.model.parts[0].type === "command") {
  const {cmd} = parseCommandString(this.props.model.parts[0].text);
  - if (CommandMap.get(cmd).category !== CommandCategories.messages) {
  + if (!CommandMap.has(cmd) || CommandMap.get(cmd).category !== CommandCategories.messages) {
  isTyping = false;
  }
  }
  