Add missing headers to AMI UnParkedCall event to uniquely identify the call.

The AMI UnParkedCall event was missing the Parkinglot and Uniqueid headers
that the AMI ParkedCall event contains.

(closes issue ASTERISK-19240)
Reported by: Michael Yara
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Merged revisions 354116 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 354119 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@354120 65c4cc65-6c06-0410-ace0-fbb531ad65f3