Get line and channel with a little more care during keybutton handling

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5495 43c1dc8c-776e-4df2-8ef1-6e829299be21
Check for existing device->session wenn setting SCCP_DEVICE_IP

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5496 43c1dc8c-776e-4df2-8ef1-6e829299be21
Initialize variables, to show cleaner gdb output

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5497 43c1dc8c-776e-4df2-8ef1-6e829299be21