TT#14008 fix kernel module for older compilers

Dummy-define RHEL_RELEASE_VERSION() if not present so older compilers
don't stumble over it

closes #1309

Change-Id: I0815950bc92cc0d6e0c2979c32bf568f23b5cb55

kernel-module/xt_RTPENGINE.c

@@ -47,6 +47,11 @@ MODULE_LICENSE("GPL");
 MODULE_IMPORT_NS(CRYPTO_INTERNAL);
 #endif
 
+// fix for older compilers
+#ifndef RHEL_RELEASE_VERSION
+#define RHEL_RELEASE_VERSION(x,y) 0
+#endif
+