sys-apps/systemd: remove the networkd-default-to-kernel-IPForwarding-setting.patch

According to https://github.com/systemd/systemd-stable/blob/v256/src/network/networkd-network.c#L470,
the forwarding settings have changed on systemd 256.

From the discussions upstream, if a systemd is configured to manage an interface,
it will manage it completely, and it will set that interface to not forward packets
by default.

From the current systemd code, it would be easy to either enable the forwarding or disable it,
but there does not seem to be a way now to inherit it from the sysctl / kernel implementation.

sdk_container/src/third_party/coreos-overlay/sys-apps/systemd/files/0002-networkd-default-to-kernel-IPForwarding-setting.patch

@@ -1,24 +0,0 @@
-From e3fd50ec704b5d48e9d756c1cc5c40e72b7d1fa4 Mon Sep 17 00:00:00 2001
-From: Nick Owens <nick.owens@coreos.com>
-Date: Tue, 2 Jun 2015 18:22:32 -0700
-Subject: [PATCH 2/8] networkd: default to "kernel" IPForwarding setting
-
----
- src/network/networkd-network.c | 1 +
- 1 file changed, 1 insertion(+)
-
-diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
-index dcd3e5ae12..2ae481d1ec 100644
---- a/src/network/networkd-network.c
-+++ b/src/network/networkd-network.c
-@@ -461,6 +461,7 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
-                 .link_local = _ADDRESS_FAMILY_INVALID,
-                 .ipv6ll_address_gen_mode = _IPV6_LINK_LOCAL_ADDRESS_GEN_MODE_INVALID,
- 
-+                .ip_forward = _ADDRESS_FAMILY_INVALID,
-                 .ipv4_accept_local = -1,
-                 .ipv4_route_localnet = -1,
-                 .ipv6_privacy_extensions = _IPV6_PRIVACY_EXTENSIONS_INVALID,
--- 
-2.34.1
-