setup: remove -ggdb compilation flag on macOS
setup: remove -ggdb compilation flag on macOS

macOS uses clang instead of gcc since a few versions now. -ggdb argument
is for GNU gcc:
-ggdb
    Produce debugging information for use by GDB. This means to use the
    most expressive format available (DWARF, stabs, or the native format
    if neither of those are supported), including GDB extensions if at
    all possible.

I also never used gdb to debug internal pyscard code on macOS.

LudovicRousseau/pyscard,LudovicRousseau/pyscard,LudovicRousseau/pyscard