Update revisionnumber to latest repository revision, during every run of make instead of configure, so that sccp show version, can output the correct one.

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5134 43c1dc8c-776e-4df2-8ef1-6e829299be21
Update debug comments for sccp_channel_endcall

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5135 43c1dc8c-776e-4df2-8ef1-6e829299be21
Fix segfault when device->active_channel->line = 0x0

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5136 43c1dc8c-776e-4df2-8ef1-6e829299be21