libmicrohttpd: enable parallel building

Changed files
+2
pkgs
development
libraries
libmicrohttpd
+2
pkgs/development/libraries/libmicrohttpd/generic.nix
···
libintl
];
+
enableParallelBuilding = true;
+
preCheck = ''
# Since `localhost' can't be resolved in a chroot, work around it.
sed -i -e 's/localhost/127.0.0.1/g' src/test*/*.[ch]