Fix scheduled_hangup / scheduled_digit refcount.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5725 43c1dc8c-776e-4df2-8ef1-6e829299be21
Fix: digittimeout / scheduled_hangup / refcount

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5726 43c1dc8c-776e-4df2-8ef1-6e829299be21