MINOR: resolvers: Use milliseconds for cached items in resolver responses

The last time when an item was seen in a resolver responses is now stored in
milliseconds instead of seconds. This avoid some corner-cases at the
edges. This also simplifies time comparisons.

(cherry picked from commit 55c1c4053f70bf53adfcd5067fa959e20f2b44fe)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
2 files changed