configure.ac: Drop copying of include files
configure.ac: Drop copying of include files

The comment suggests this is for windows compilation. It should be easily
possible to add the source directory as an include path to the windows
compiler, too, so drop this. (Otherwise this should better be done using
AC_CONFIG_COMMANDS.)

mrjimenez/pupnp,mrjimenez/pupnp,mrjimenez/pupnp,mrjimenez/pupnp