message: Don't show Matrix-namespaced push rules which the server doesn't declare
  So that users can't change push rules they don't have. Similar to the behaviour in
diff: @@ -704,6 +704,10 @@ module.exports = React.createClass({
  const rows = [];
  for (const i in this.state.vectorPushRules) {
  const rule = this.state.vectorPushRules[i];
  + if (rule.rule === undefined && rule.vectorRuleId.startsWith(".m.")) {
  + console.warn(`Skipping render of rule ${rule.vectorRuleId} due to no underlying rule`);
  + continue;
  + }
  //console.log("rendering: " + rule.description + ", " + rule.vectorRuleId + ", " + rule.vectorState);
  rows.push(this.renderNotifRulesTableRow(rule.description, rule.vectorRuleId, rule.vectorState));
  }
  