set default socket before parsing the config

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5072 43c1dc8c-776e-4df2-8ef1-6e829299be21
set correct port_str size

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5073 43c1dc8c-776e-4df2-8ef1-6e829299be21
set default bind-port

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5074 43c1dc8c-776e-4df2-8ef1-6e829299be21