Use suckless scroll for scrollback

config.def.h

@@ -27,7 +27,7 @@ static int borderpx = 2;
 static char *shell = "/bin/sh";
 char *utmp = NULL;
 /* scroll program: to enable use a string like "scroll" */
-char *scroll = NULL;
+char *scroll = "scroll";
 char *stty_args = "stty raw pass8 nl -echo -iexten -cstopb 38400";
 
 /* identification sequence returned in DA and DECID */