Revert "Adding additional mirrors, changing the default"

This reverts commit b3e879111abcf06c78021b55e677d8d2e546eb27.

src/boot.cfg

@@ -7,7 +7,7 @@ set site_name netboot.xyz
 set boot_domain boot.netboot.xyz
 
 # set mirror domain
-set mirror mirrors.digitalocean.com
+set mirror mirror.rackspace.com
 
 # set location of memdisk
 set memdisk http://${boot_domain}/memdisk

src/mirrors.ipxe

@@ -3,9 +3,9 @@
 # Basic attempt at mirror rotation
 
 :mirror_start
-iseq ${mirror} mirrors.digitalocean.com && set mirrors.kernel.org && goto mirror_end ||
-iseq ${mirror} mirrors.kernel.org && set mirror mirror.rackspace.com && goto mirror_end ||
-iseq ${mirror} mirror.rackspace.com && set mirror mirrors.digitalocean.com && goto mirror_end ||
+iseq ${mirror} mirror.rackspace.com && set mirror mirrors.kernel.org && goto mirror_end ||
+iseq ${mirror} mirrors.kernel.org && set mirror blah.mirror.blah.com && goto mirror_end ||
+iseq ${mirror} blah.mirror.blah.com && set mirror mirror.rackspace.com && goto mirror_end || 
 echo Setting mirror to ${mirror}...
 
 :mirror_end