DOC: "addr" parameter applies to both health and agent checks

It was not obvious in the documentation that the server's "addr"
parameter applies to both the agent and the health check.

backport: 1.5 and above
(cherry picked from commit 13f835380f6e517ac0d393ce10567a4f7f97fecf)
(cherry picked from commit a06b4867b771cb18e6f7c86c4c8dd9e50fdb8364)
1 file changed