#164 Retry of ACK using incorrect branch header.

[Brendan ONeill]

sipp version v3.7.1
Following a ACK lost in the network and then a subsequent INVITE sent by SIPP , a retry response(401 in this case) is received. The retry of the ACK has now sends the branch of the last INVITE (with the [last_via] variable) rather than the Branch of the original INVITE.
A similar issue happened with CSEQ in a previous sipp version(3.3) which i resolved by assigning the [cseq] to a variable. (havent confirmed if it still happens in 3.7) I can do the same thing with [last_via] but it looks like a bug that needs attention. A retry should generate the exact message as the original.

[Brendan ONeill]

scenario file attached.