Fix a null pointer dereference issue

Updated the 'socket_send4' routine to fix an unlikely, yet possible
null pointer dereference issue. It could occur if the two macros
below are undefined

   struct cmsghdr *cmsg = NULL;

   #ifdef IP_PKTINFO
        ...
        cmsg = CMSG_FIRSTHDR (&msgh);

   #elif defined IP_SENDSRCADDR
        ...
        cmsg = CMSG_FIRSTHDR (&msgh);

   #endif

   msgh.msg_controllen = cmsg->cmsg_len;

It was caught by a cppcheck(1) run. Thanks to Rahul Sundaram for
reporting this issue.
Version changed to 1.05.9.

Changed version.h, configure.ac and RPM spec file to upgrade version
to 1.05.9.