contrib: increase pjsip maximum local hosts capacity

This maximum was 8 (in fact 7 as pjsip reserves 1 room for internal usage).
Linux kernel supports 16 IPv6 that could overload this size and prevents
IPv4 to be added.
Increasing this number to 32.

Change-Id: I61c12c7fdb1dace97c524e681bd6fdaa239e1c11