Revert "use -Wl on -no-undefined as it is a linker option:"

This reverts commit 57b1d0dc7f4aa49b5dc0c18225f51951119bd58c.

Remove redundant -no-undefined, make sure only the one that gets
into Makefiles directly remains, remove -Wl prefix from it.

git-svn-id: https://gnunet.org/svn/gnunet@32037 140774ce-b5e7-0310-ab8b-a85725594a96