logmeter: resolve hostname rather than use raw IP address

Signed-off-by: Colin Ian King <colin.king@canonical.com>
logmeter: Add some extra retries if telnet connections fail on meter

The lab is seeing some connection failures which are breaking the
logmeter.  Adding an exception handler and retries makes it a little
more resiliant to sporadic fluke telnet socket connection errors.

Signed-off-by: Colin Ian King <colin.king@canonical.com>