gcc 10 and build over 4.13.3

[FAMILIAR-project]

In file included from scripts/selinux/genheaders/genheaders.c:18:
./security/selinux/include/classmap.h:242:2: error: #error New address family defined, please update secclass_map.
  242 | #error New address family defined, please update secclass_map.
      |  ^~~~~
make[3]:  [scripts/Makefile.host:101: scripts/selinux/genheaders/genheaders] Error 1
make[2]:  [scripts/Makefile.build:561: scripts/selinux/genheaders] Error 2
make[1]: *** [scripts/Makefile.build:561: scripts/selinux] Error 2

this thread explains everything: https://lkml.org/lkml/2019/4/22/794

workaround: downgrade glibc (2.28 instead of 2.29 says)
in general the challenge is now to have gcc versions together with good libc/glibc versions (see also #27)
another attitude is to apply patch but I'm not that comfortable with this idea, I really would like we setup a Debian-like image with good versions