When the Optional Data surpasses 130 bytes, it is not sent as part of
SCCP CR, CC, CREF or RLSD messages, but gets sent separately in a Data
Form 1.
Make this 130 user configurable. This is specified to be 130 bytes
exactly, but to interop with non-conforming peers, make this limit
adjustable per cs7 instance, via osmo_sccp_vty_init().
Add and test new VTY config:
cs7 instance N
sccp max-optional-data (<0-999999>|standard)
Related: ITU-T Q.713 4.2 to 4.5
Related: Ia68dad973ef18513b52f5accb5264c557c7295ea osmo-ttcn3-hacks
Related: SYS#6423
Change-Id: If35697234796af8943691b2de62218e7dc93a08c
Neels Hofmeyr
a0fbeeb4d2