-remove m4 macro to check for plibc
-remove m4 macro to check for plibc

git-svn-id: d3d46767b8f15aa15dc28b4413db96165ce057f7@32412 140774ce-b5e7-0310-ab8b-a85725594a96

madebyjeffrey/lightning,svn2github/libmicrohttpd,svn2github/libmicrohttpd,scottjg/libmicrohttpd,redBorder/libmicrohttpd,madebyjeffrey/lightning,madebyjeffrey/lightning,madebyjeffrey/lightning,redBorder/libmicrohttpd,scottjg/libmicrohttpd,scottjg/libmicrohttpd,svn2github/libmicrohttpd,redBorder/libmicrohttpd,svn2github/libmicrohttpd