Synchronize SUB_HDRMOD definition to match smbdefs.h

./scfg.h:80:9: warning: 'SUB_HDRMOD' macro redefined [-Wmacro-redefined]

src/sbbs3/scfg/scfg.h

@@ -77,7 +77,7 @@
 /* Constants */
 /*************/
 
-#define SUB_HDRMOD	(1L<<31)		/* Modified sub-board header info */
+#define SUB_HDRMOD	(1<<31)		/* Modified sub-board header info */
 
 #define MAX_UNIQUE_CODE_ATTEMPTS (36*36*36)