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>