base-files: update rdate server list

SVN-Revision: 25478

package/base-files/files/etc/config/timeserver

-config timeserver
-	option hostname	ac-ntp0.net.cmu.edu
-#	option interface	wan
-
 config timeserver
 	option hostname	ptbtime1.ptb.de
+#	option interface	wan
 
 config timeserver
-	option hostname	ac-ntp1.net.cmu.edu
-
-config timeserver
-	option hostname	tick.greyware.com
+	option hostname	time-a.nist.gov
 
 config timeserver
 	option hostname	ntp.xs4all.nl
@@ -18,7 +12,7 @@ config timeserver
 	option hostname	ptbtime2.ptb.de
 
 config timeserver
-	option hostname	cudns.cit.cornell.edu
+	option hostname	time-b.nist.gov
 
 config timeserver
 	option hostname	ptbtime3.ptb.de