nginx: generates config file using configure input.

The nginx config file was looking for depedencies by its own,
by doing that it was ignoring the options that were passed to
configure script. This commit deletes this config file and adds
a meta-config which is populated by configure whenever the
standalone-module is enabled.

configure.ac

@@ -707,6 +707,7 @@ AC_CONFIG_FILES([apache2/Makefile])
 fi
 if test "$build_standalone_module" -ne 0; then
 AC_CONFIG_FILES([standalone/Makefile])
+AC_CONFIG_FILES([nginx/modsecurity/config])
 fi
 if test "$build_extentions" -ne 0; then
 AC_CONFIG_FILES([ext/Makefile])