[h323plus] New PTLib release 2.10.9.3

Hi,

I just published a new maintenance release for PTLib: https://github.com/willamowius/ptlib/releases

Version 2.10.9.3 fixes a few bugs, including a race condition when closing PChannels, that can lead to a crash and another deadlock fix.

It adds support for SNMP SET in PSNMPServer (all class signatures remain unchanged) and various compile fixes for recent compilers.

Happy holidays!

Jan