Correct ast_channel_named_pickupgroups_set to ast_channel_named_callgroups_set (Issue Reported by Antonio Guirado)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5181 43c1dc8c-776e-4df2-8ef1-6e829299be21
Check if line->pickupgroup/line->named_pickupgroup have been set before trying directed pickup

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5182 43c1dc8c-776e-4df2-8ef1-6e829299be21