x11-fm: remove 'Created by' lines

A big Thank You to the original contributors of these ports:

  *  Alejandro Pulver <alejandro@varnet.biz>
  *  Alexey Dokuchaev <danfe@FreeBSD.org>
  *  Anders Nordby <anders@fix.no>
  *  Beñat Gonzalez Etxepare <bbtruk@users.sourceforge.net>
  *  Geyer Klaus
  *  Gustau Perez i Querol <gustau.perez@gmail.com>
  *  Heiner <h.eichmann@gmx.de>
  *  Jens K. Loewe <bsd@tuxproject.de>
  *  Lars Engels <lars.engels@0x20.net>
  *  Martin Tournoij <carpetsmoker@xs4all.nl>
  *  Oliver Lehmann <oliver@FreeBSD.org>
  *  Olivier Cochard-Labbe <olivier@FreeBSD.org>
  *  Olivier Duchateau
  *  Rodrigo Osorio <rodrigo@freebsd.org>
  *  Simon Dick <simond@irrelevant.org>
  *  Zhihao Yuan <lichray@gmail.com>
  *  ade, archie
  *  lukin
  *  minoura@netbsd.org
  *  ptiJo
  *  trevor

With hat:	portmgr