There was no info about supported sections for "max-session-srv-conns"
proxy directive. A quick look at the code tells us that it may be used
in proxies with the FE capability set.
Set the maximum number of outgoing connections we can keep idling for a given
client session. The default is 5 (it precisely equals MAX_SRV_LIST which is
defined at build time).
+ May be used in sections : defaults | frontend | listen | backend
+ yes | yes | yes | no
maxconn <conns>
Fix the maximum number of concurrent connections on a frontend