main/pjproject: enable IPv6

Hey,

I was trying to use asterisk with ipv6 in a alpine container, after much debugging i found that v6 is disabled in pjproject per default.

This MR uses pjprojects "site override" feature(https://github.com/pjsip/pjproject/blob/13741d9eff3fce4f1c88715881fa85f454f33737/pjlib/include/pj/config.h#L317) to enable IPv6. This will then allow asterisk to use the ipv6 support.

IPv6 support should cause no major issues, as upstream asterisk already ships with a pjproject with ipv6 enabled(https://github.com/asterisk/asterisk/blob/master/third-party/pjproject/patches/config_site.h#L23).

The flipped switch is documented here: https://github.com/pjsip/pjproject/blob/13741d9eff3fce4f1c88715881fa85f454f33737/pjlib/include/pj/config.h#L658

I had to bump asterisk too, as i got segfaults otherwhise(Similar to #15564 (closed)?). I have these package running now in a test instance and will play with them :)

Kind Regards, Stephan