Convert some warnings into debug messages since they can exist under perfectly...

Convert some warnings into debug messages since they can exist under perfectly normal circumstances that the user shouldn't care about (issue #7894 reported by stephen_dredge)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@42264 65c4cc65-6c06-0410-ace0-fbb531ad65f3