Fix cisco default application variant

[dspicuzzbbn]

This is a weird one I found, and I'm open to solving it a different way. Here's the original config (added as a testcase):

application
 service something http://some.url/some.page
 !
 global
  service alternate Default
 !
!

References:

• https://www.cisco.com/c/en/us/support/docs/voice/media-gateway-control-protocol-mgcp/29960-configsrst-mgcpfallback.html#solution1a
• http://puck.nether.net/pipermail/cisco-voip/2006-March/010959.html

[arifogel]

This is fine for now since we throw this away anyway.