A bug was found in "mod_authn_core.c" which is an Apache module and a fix has been given to it,
it has been given in the simplest form of .c file (C code)
apparently i need to compile it and replace my existing module file and it should work
Suggested (Working) patch to be replaced with (from the bug report)
it suppose to be very easy to do with the right knowledge and i think this question is generic and can help others most surely in compiling different mods.
well i found out that apache2 has a built in compiler for mods called apxs2:
sudo apxs2 -c -i mod_authn_core.c
echo “LoadModule mod_authn_core /usr/lib/apache2/modules/mod_authn_core.so” > /etc/apache2/mods-available/mod_authn_core.load