Compiling slony against PG 9.4 gives compiler warnings because the
definition of HAVE_POSIX_SIGNALS has changed. This is defined in pg_config
so we do not really need to redefine it in the config.h slony provides.
We leave the configure check in place to we just don't include it in
the header
#undef HAVE_GETACTIVESNAPSHOT
/* Set to 1 if we have POSIX signals */
-#undef HAVE_POSIX_SIGNALS
+/**#undef HAVE_POSIX_SIGNALS**/
/* Set to 1 if we have PGPORT */
#undef HAVE_PGPORT