vty: mncc cfg: separate the 'mncc' from 'mncc-guard-timeout'

I want to add 'mncc internal' and 'mncc external' commands, and IMHO makes most
sense to have a common 'mncc' keyword to start MNCC config commands with. To
put it in terms of VTY online help:

  OsmoMSC(config-msc)# mncc ?
    internal       Use internal MNCC handler
    external       Use internal MNCC handler
    guard-timeout  Set global guard timeout

So far only the 'guard-timeout' exists, I want to add 'internal' and 'external'
in a subsequent commit.

Keep the old command 'mncc-guard-timeout' as deprecated alias. That means it
still works from old config files, but online documentation will omit it.

On 'write', write back the new format instead.

Rationale: see I2ec59d5eba407f83295528b51b93678d446b9cee

Change-Id: I52d69af48e1ddc87b3fb54bf66a01b1b8cbf5abe

0 files changed, 0 insertions, 0 deletions