stage2: clean unused/obsolete patch (#187)

stage2/01-sys-tweaks/00-patches/06-rc_local.diff

@@ -1,15 +0,0 @@
-Index: jessie-stage2/rootfs/etc/rc.local
-===================================================================
---- jessie-stage2.orig/rootfs/etc/rc.local
-+++ jessie-stage2/rootfs/etc/rc.local
-@@ -11,4 +11,10 @@
- #
- # By default this script does nothing.
- 
-+# Print the IP address
-+_IP=$(hostname -I) || true
-+if [ "$_IP" ]; then
-+  printf "My IP address is %s\n" "$_IP"
-+fi
-+
- exit 0