remove broken mirrors

mk/mirrors.mk

@@ -36,13 +36,11 @@ MASTER_SITE_GNU?=	\
   	ftp://ftp.sunet.se/pub/gnu/ \
 
 MASTER_SITE_SOURCEFORGE?=	\
-	http://netcologne.dl.sourceforge.net/sourceforge/ \
-	http://skylink.dl.sourceforge.net/sourceforge/ \
-	http://heanet.dl.sourceforge.net/sourceforge/ \
 	http://jaist.dl.sourceforge.net/sourceforge/ \
+	http://heanet.dl.sourceforge.net/sourceforge/ \
+	http://netcologne.dl.sourceforge.net/sourceforge/ \
 	http://nchc.dl.sourceforge.net/sourceforge/ \
 	http://kent.dl.sourceforge.net/sourceforge/ \
-	http://surfnet.dl.sourceforge.net/sourceforge/ \
 	http://ufpr.dl.sourceforge.net/sourceforge/ \
 	http://easynews.dl.sourceforge.net/sourceforge/ \