fix build with non-static builds

There is a typo in the CFLAGS and zmq is not being linked in. Apparently non-static builds are not being tested? :) If there is a particular reason to discourage linking against system libraries, perhaps this feature should be removed (and in that case linking on x86-64 Linux systems with 32 bit support, where the lib dir is lib64, should be fixed), otherwise, this fixes dynamic linkage builds.