add support for varnish plugin categories

Since commit collectd-4.10.0-88-g02e12db the varnish plugin groups collected
values in categories. The collectd filestructure used for varnish is now:

  <plugin>-<category>-<plugin_instance>/<type>-<type_instance>

Because this isn't distinguishable from a regular plugin like df, ...

  df-var-tmp/df_complex-free.rrd ("var" isn't the category here)

... the category is only set with the varnish plugin.

Reported-by: Jonathan Huot <jonathan.huot@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/detail.php b/detail.php
index a7b2cd4..503a411 100644
--- a/detail.php
+++ b/detail.php
@@ -14,6 +14,7 @@ if (empty($_GET['y']))
 $host = validate_get(GET('h'), 'host');
 $plugin = validate_get(GET('p'), 'plugin');
 $pinstance = validate_get(GET('pi'), 'pinstance');
+$category = validate_get(GET('c'), 'category');
 $type = validate_get(GET('t'), 'type');
 $tinstance = validate_get(GET('ti'), 'tinstance');
 $width = GET('x');