[PGPRO-5691] added forgotten #include

Author: kulaginm

Diff for: engine.h

@@ -23,7 +23,7 @@
 /*  #include "storage/smgr.h" */
 /*  #include "utils/relcache.h" */
 #include "access/hash.h"
-
+#include "utils/guc.h"
 
 /* Persistent copy of ptrack.map to restore after crash */
 #define PTRACK_PATH "global/ptrack.map"