message: Fix to allow subsequent group profile requests if one fails
  Also, delete the groupProfilePromise immediately after setting
  the group profile (the first if-statement will prevent a new
  request from being started).
diff: @@ -157,17 +157,25 @@ class FlairStore {
  this._groupProfilesPromise[groupId] = matrixClient.getGroupProfile(groupId);
  }
  - const profile = await this._groupProfilesPromise[groupId];
  + let profile;
  + try {
  + profile = await this._groupProfilesPromise[groupId];
  + } catch (e) {
  + // Don't retry, but allow a retry when the profile is next requested
  + delete this._groupProfilesPromise[groupId];
  + return;
  + }
  +
  this._groupProfiles[groupId] = {
  groupId,
  avatarUrl: profile.avatar_url,
  name: profile.name,
  shortDescription: profile.short_description,
  };
  + delete this._groupProfilesPromise[groupId];
  setTimeout(() => {
  delete this._groupProfiles[groupId];
  - delete this._groupProfilesPromise[groupId];
  }, GROUP_PROFILES_CACHE_BUST_MS);
  return this._groupProfiles[groupId];
  