Fix cifs mount options for guest access (#74)

* Fix cifs mount options when no username is supplied

* Update to use sec=none

cifs_mount.sh

@@ -199,7 +199,7 @@ fi
 
 if [ "$USERNAME" == "" ]
 then
-	MOUNT_OPTIONS="guest"
+	MOUNT_OPTIONS="sec=none"
 else
 	MOUNT_OPTIONS="username=$USERNAME,password=$PASSWORD"
 	if [ "$DOMAIN" != "" ]
@@ -341,4 +341,4 @@ else
 fi
 
 echo "Done!"
-exit 0
+exit 0