message: Disallow empty string
diff: @@ -147,7 +147,8 @@ IrcServer.prototype.getJoinRule = function() {
  };
  IrcServer.prototype.areGroupsEnabled = function() {
  - return this.config.dynamicChannels.groupId !== undefined;
  + return this.config.dynamicChannels.groupId !== undefined &&
  + this.config.dynamicChannels.groupId !== "";
  };
  IrcServer.prototype.getGroupId = function() {
  