Update check-config.sh

Add IP_NF_MANGLE to "Generally Required" kernel features, since it appears to be necessary for Docker Swarm to work.

Closes https://github.com/moby/moby/issues/46636

Signed-off-by: Stephan Henningsen <stephan-henningsen@users.noreply.github.com>
(cherry picked from commit cf9073397cf8538b168501d9467865bd0059a9e7)
Conflicts: contrib/check-config.sh
Signed-off-by: Bjorn Neergaard <bjorn.neergaard@docker.com>

contrib/check-config.sh

@@ -196,7 +196,7 @@ flags=(
 	CGROUPS CGROUP_CPUACCT CGROUP_DEVICE CGROUP_FREEZER CGROUP_SCHED CPUSETS MEMCG
 	KEYS
 	VETH BRIDGE BRIDGE_NETFILTER
-	IP_NF_FILTER IP_NF_TARGET_MASQUERADE
+	IP_NF_FILTER IP_NF_MANGLE IP_NF_TARGET_MASQUERADE
 	NETFILTER_XT_MATCH_{ADDRTYPE,CONNTRACK,IPVS}
 	NETFILTER_XT_MARK
 	IP_NF_NAT NF_NAT