When the percona-cluster charm sets an access-network but the default
unit-get address is not on that network extra shared-db relations get
executed. This is specifically a problem when running upgrades and
trying to avoid API downtime.
The root cause is that the access-network is not checked until the
SharedDBContext is consulted. But then db_joined function will
change it back to the wrong ip on subsequent runs.
This change adds a check for access-network on the relation during
the db_joined function and pushes IP selection off to
get_relation_ip.
Charm helpers sync to pull in changes to get_relation_ip.
Change-Id: Ifc22d61f1de1092306b98d30fbea01fead855d14
Partial-bug: #1677647
e7317bf571