Also remove advanced syslinux config files for gtk

Note that AFAICT removing these files is unnecessary as they should not
be included in the tarball if the file f3.txt.withgtk is not present.

tools/boot/lenny/boot-x86

@@ -184,8 +184,12 @@ if [ "$THISTYPE" = "isolinux" ]; then
 		fi
 	else
 		# Remove gtk isolinux config files.
+		# FJP: AFAICT this is redundant: if f3.txt.withgtk is not
+		# included then the *gtk* files will not be either.
 		rm -f boot$N/$ISOLINUXDIR/gtk.cfg
 		rm -f boot$N/$ISOLINUXDIR/amdgtk.cfg
+		rm -f boot$N/$ISOLINUXDIR/adgtk.cfg
+		rm -f boot$N/$ISOLINUXDIR/adamdgtk.cfg
 	fi
 	rm -f boot$N/$ISOLINUXDIR/isolinux.cfg.with* 2>/dev/null || true