node: don't ignore timeout config option

According to pwydrych in ticket #1258 :

Adding timeout to munin-node.conf has no effect:

    $ grep timeout /etc/opt/munin/munin-node.conf
    timeout 240

    $ sudo /opt/munin/sbin/munin-node

    $ telnet 127.0.0.1 4949
    Trying 127.0.0.1...
    Connected to localhost.
    Escape character is '^]'.
    # munin node at [***]
    Connection closed by foreign host.

    $ egrep 'Peer|timeout' /opt/munin/log/munin/munin-node.log
    2012/09/18-08:48:49 CONNECT TCP Peer: "127.0.0.1:22230" Local: "127.0.0.1:4949"
    2012/09/18-08:49:49 [91860] Node side timeout while processing: '<no command received yet>'

The variable is not passed to Munin::Node::Service->new:

    $ cat -n node/sbin/munin-node
    [...]
        67      my $services = Munin::Node::Service->new(
        68          servicedir => $servicedir,
        69          defuser    => $config->{defuser},
        70          defgroup   => $config->{defgroup},
        71          pidebug    => $PIDEBUG,
        72      );
    [...]

Closes: #1258