We actually need to link against libz, as neo libraries are often static

This reverts commit 3c0630a797.

src/libfast/Makefile.am

@@ -3,6 +3,6 @@ lib_LTLIBRARIES = libfast.la
 libfast_la_SOURCES = context.h dispatcher.c request.h session.h \
   controller.h dispatcher.h request.c session.c filter.h smtp.c smtp.h
 libfast_la_LIBADD = $(top_builddir)/src/libstrongswan/libstrongswan.la \
-  -lfcgi -lneo_cgi -lneo_cs -lneo_utl $(PTHREADLIB)
+  -lfcgi -lneo_cgi -lneo_cs -lneo_utl -lz $(PTHREADLIB)
 INCLUDES = -I$(top_srcdir)/src/libstrongswan -I/usr/include/ClearSilver
 AM_CFLAGS = -rdynamic