Fixed @TZ timezone kludge line for 64-bit GCC builds.

src/sbbs3/msgtoqwk.cpp

@@ -246,7 +246,7 @@ ulong sbbs_t::msgtoqwk(smbmsg_t* msg, FILE *qwk_fp, long mode, int subnum
 	}
 
 	if(msg->hdr.when_written.zone && mode&QM_TZ)
-		size+=fprintf(qwk_fp,"@TZ: %04x%c",msg->hdr.when_written.zone,QWK_NEWLINE);
+		size+=fprintf(qwk_fp,"@TZ: %04hx%c",msg->hdr.when_written.zone,QWK_NEWLINE);
 
 	if(msg->replyto!=NULL && mode&QM_REPLYTO)
 		size+=fprintf(qwk_fp,"@REPLYTO: %s%c"