busybox: cron support is optional. don't install crond init by default

packages/sysutils/busybox/install

@@ -78,3 +78,9 @@ USER_PWD="`$ROOT/$TOOLCHAIN/bin/cryptpw -m sha512 $USER_PASSWORD`"
 
     mkdir -p $INSTALL/usr/www/error
       echo "404" > $INSTALL/usr/www/error/404.html
+
+  # cron support
+    if [ "$CRON_SUPPORT" = "yes" ] ; then
+      mkdir -p $INSTALL/etc/init.d
+      cp $PKG_DIR/scripts/09_crond $INSTALL/etc/init.d/
+    fi