Fix alreadySetEntries[] when parsing codec disallow/allow preferences (Reported by Phillipe Teissier).

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4821 43c1dc8c-776e-4df2-8ef1-6e829299be21
Fix sccp_parse_allow_disallow to skip empty entries (for example from default) without resetting codecs.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@4822 43c1dc8c-776e-4df2-8ef1-6e829299be21