roles/samba: Remove socket options

The `socket options` directive does not need to be specified in
`smb.conf`. I think I copied it from an example many years ago, and
never bothered to remove it. It is definitely not required, most likely
not helping performance at all, and most likely hindering it.

roles/samba/templates/smb.conf.j2

@@ -20,8 +20,6 @@ security = {{ samba_security }}
 {% endfor %}
 {% endif %}
 
-socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
-
 printing = bsd
 printcap name = /dev/null
 load printers = no