Missed reference in null client for CL_PacketEvent

[Shared] Workarounds for zlib and libpng to compile on macOS 13.5.2 (…

…Apple M1) using Xcode 14.3.1 (14E300c).

The same workarounds were also used to compile on macOS 11.4 (Apple M1) using Xcode 12.5.1 (12E507).