core: cfg parser: allow negative numbers in modparams

(cherry picked from commit d4b2eee2e4f0e5a1fe4b5ea17d78d51a6fab70c7)

cfg.y

@@ -1604,7 +1604,7 @@ module_stm:
 			 yyerror("Can't set module parameter");
 		}
 	}
-	| MODPARAM LPAREN STRING COMMA STRING COMMA NUMBER RPAREN {
+	| MODPARAM LPAREN STRING COMMA STRING COMMA intno RPAREN {
 	#ifdef SHM_MEM
 		if (!shm_initialized() && init_shm()<0) {
 			yyerror("Can't initialize shared memory");