message: Speed up getMappingsForChannelByOrigin by 2 orders of magnitude
diff: @@ -299,11 +299,8 @@ DataStore.prototype.getMappingsForChannelByOrigin = function(server, channel, or
  throw new Error("origin must be string or array of strings");
  }
  let remoteId = IrcRoom.createId(server, channel);
  - return this._roomStore.getEntriesByLinkData({}).then((entries) => {
  + return this._roomStore.getEntriesByRemoteId(remoteId).then((entries) => {
  return entries.filter((e) => {
  - if (!e.remote || e.remote.getId() !== remoteId) {
  - return false;
  - }
  if (allowUnset) {
  if (!e.data || !e.data.origin) {
  return true;
  