Fix improper warning introduced by r342927 and more tweaks

Changeset r342927 introduced a warning which was only supposed to be
emitted when a found realtime peer had an empty (or no) name. It turned
out that there were some inconsistencies left. Now found peers with an
empty name are explicitly ignored like before r342927 but better.

Reviewed by: Stefan Schmidts, Terry Wilson

Review: https://reviewboard.asterisk.org/r/1560
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Merged revisions 343181 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 343192 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@343219 65c4cc65-6c06-0410-ace0-fbb531ad65f3