complibs/ppl: remove unnecessary (and confusing) --enable-cxx configure switch.

PPL does not use the "--enable-cxx" configure switch at all; it's
possibly a cut-and-paste leftover from 'gmp.sh'. (PPL is written in C++
natively, so it doesn't make much sense to have to enable C++; GMP, on
the other hand, is written in C with an optional C++ wrapper.)

Signed-Off-By: Anthony Foiani <anthony.foiani@gmail.com>

 #!/bin/sh

 # Needed for systems without gettext

 $* -xc -o /dev/null - > /dev/null 2>&1 << EOF

 #include <libintl.h>

 int main()

 {

 	gettext("");

 	return 0;

 }

 EOF

 if [ ! "$?" -eq "0"  ]; then

 	echo -DKBUILD_NO_NLS;

 fi