warning: implicit conversion of NULL constant to 'CFStringEncoding'

[ryandesign]

Compiling enigma (latest git source as of yesterday) on macOS 12 produces this warning:

ecl_sys_localename.cc:749:51: warning: implicit conversion of NULL constant to 'CFStringEncoding' (aka 'unsigned int') [-Wnull-conversion]
    const char *tmp = CFStringGetCStringPtr(name, NULL);
                      ~~~~~~~~~~~~~~~~~~~~~       ^~~~
                                                  0
1 warning generated.

Instead of NULL or 0 you should presumably be using one of the constants documented by Apple.