(Backport) Fix compile error for ast106, Fix pbx_channel_ref for other channel drivers

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/branches/V4.1@4756 43c1dc8c-776e-4df2-8ef1-6e829299be21
backport trunk changes 4759:4761

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/branches/V4.1@4762 43c1dc8c-776e-4df2-8ef1-6e829299be21
set version to 4.1.1

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/branches/V4.1@4771 43c1dc8c-776e-4df2-8ef1-6e829299be21