message: Don't crash if a keyshare request is removed
  ...during the time the dialog is displayed.
  Fixes (hopefully)
diff: @@ -111,6 +111,12 @@ export default class KeyRequestHandler {
  this._currentUser = null;
  this._currentDevice = null;
  + if (!this._pendingKeyRequests[userId] || !this._pendingKeyRequests[userId][deviceId]) {
  + // request was removed in the time the dialog was displayed
  + this._processNextRequest();
  + return;
  + }
  +
  if (r) {
  for (const req of this._pendingKeyRequests[userId][deviceId]) {
  req.share();
  