Fix sensors rrd name issue

Use last instead of first, as last won't flush rrdcached
Only stream_select if timeout > 0
Attempt to fix mysql

html/pages/device/ports.inc.php

@@ -57,9 +57,12 @@ $graph_types = array(
     'upkts'     => 'Unicast Packets',
     'nupkts'    => 'Non-Unicast Packets',
     'errors'    => 'Errors',
-    'etherlike' => 'Etherlike',
 );
 
+if ($config['enable_ports_etherlike']) {
+    $graph_types['etherlike'] = 'Etherlike';
+}
+
 foreach ($graph_types as $type => $descr) {
     echo "$type_sep";
     if ($vars['graph'] == $type && $vars['view'] == 'graphs') {