fixes escape to extensions 'o' and 'a', for digits '0' and '*'

(closes issue #16437)
Reported by: alecdavis
Tested by: alecdavis
Patch
	extension_o_a_fix.diff.txt uploaded by alecdavis (license 585)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@234893 65c4cc65-6c06-0410-ace0-fbb531ad65f3