[asterisk-ss7] chan_ss7 0.9 segfault

[Anton]

On a PC with a little memory amount (128m) - seems there is an issue in 0.9 (0.8.4 too) - i've been getting a stable segfault in the line 
while processing GRA on some of the CIC.

0.9
struct ss7_chan* pvt = event->isup.link->linkset->cic_list[isup_msg.cic];