src: remove <unistd.h> from node_os.cc
The file does not use sysconf() and its use of gethostname() has been removed, so including <unistd.h> appears to be unnecessary.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
The file does not use sysconf() and its use of gethostname() has been removed, so including <unistd.h> appears to be unnecessary.