Fix redial button activation if no database entry, for lineInstance=0 / callid=0 (ie. Base Screen with no activate line key mode). On De-mask the button once, when it switches from no lastDialedNumer to the First Setting.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5442 43c1dc8c-776e-4df2-8ef1-6e829299be21