[Reviewer: Ellie] Log more information when poll-sip fails

This change logs out the Call-ID and the time the OPTIONS poll was sent when a poll-sip request fails. This should make it easier to hunt through the Sprout logs for failed polls.

The resulting log is:

[UTC Aug 14 11:36:27] error    : 'poll_sprout' status failed (1) for /usr/share/clearwater/bin/poll_sprout.sh. Error: SIP poll failed to 10.238.242.172:5054 with Call-ID poll-sip-761512 at 2014-08-14 11:36:22.894016854+00:00
stderr was:
nc: connect to 10.238.242.172 port 5054 (tcp) failed: Connection refused
stdout was:
..