Suppressed LOG_ERROR on (socket error || client closed connection). When it is an error, other debug information will be printed out already. If it is a client close connection no error report should be necessary. (references #159)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5002 43c1dc8c-776e-4df2-8ef1-6e829299be21