preseed: Change mirror from local to ftp.de.debian.org

debian-inst/preseed.cfg

@@ -97,7 +97,7 @@ d-i hw-detect/load_firmware boolean true
 #d-i mirror/protocol string ftp
 d-i mirror/country string manual
 #d-i mirror/http/hostname string ftp.de.debian.org
-d-i mirror/http/hostname string 10.11.11.64:9999
+d-i mirror/http/hostname string ftp.de.debian.org
 d-i mirror/http/directory string /debian
 d-i mirror/http/proxy string