nmbd error when server name has 15 characters

[Matt Seitz]

The nmbd daemon reports an error when starting up if the netbios name is exactly 
15 characters long.  The problem appears to be in the send_announcement function 
in src/ext/samba/source/nmbd/nmbd_sendannounce.c.  Line 106 reads:

     push_string(NULL, p+5, server_name, 15, STR_ASCII|STR_UPPER|STR_TERMINATE);

The STR_TERMINATE flag adds one to the server_name length, making it greater
than maximum destination length of 15.  I'm not sure whether the correct fix is 
to increase the destination length or remove the STR_TERMINATE flag.