Widget plot.minmaxavg: Rename variable "gad" to "item"

Use same naming as for other plots.
Not a real issue but nevertheless assigned to issue Martin-Gleiss#23
Change should not affect any user of the widget

widgets/plot.html

@@ -151,16 +151,16 @@
 *
 * @see misc/fundamentals#Duration-Format
 */
-{% macro minmaxavg(id, gad, tmin, tmax, ymin, ymax, unit, axis, count) %}
+{% macro minmaxavg(id, item, tmin, tmax, ymin, ymax, unit, axis, count) %}
 	{% set tmax = (tmax|lower=='0h' or tmax==0)? 'now' : tmax %}
 	{% if once('highcharts-more') %}
 		<script src="vendor/plot.highcharts/highcharts-more.js"></script>
 	{% endif %}
 
 	<div id="{{ uid(page, id) }}" data-widget="plot.minmaxavg" data-unit="{{ unit|default('') }}"
-		 data-item="{{ implode(gad, ['min', tmin|default('1h'), tmax|default('now'), count|default(100)]) }},
-		 {{ implode(gad, ['max', tmin|default('1h'), tmax|default('now'), count|default(100)]) }},
-		 {{ implode(gad, ['avg', tmin|default('1h'), tmax|default('now'), count|default(100)]) }}"
+		 data-item="{{ implode(item, ['min', tmin|default('1h'), tmax|default('now'), count|default(100)]) }},
+		 {{ implode(item, ['max', tmin|default('1h'), tmax|default('now'), count|default(100)]) }},
+		 {{ implode(item, ['avg', tmin|default('1h'), tmax|default('now'), count|default(100)]) }}"
 		 {% if ymin is not empty %} data-ymin="{{ ymin }}" {% endif %} {% if ymax is not empty %} data-ymax="{{ ymax }}" {% endif %}
 		 {% if count is not empty %} data-count="{{ count }}" {% endif %} data-axis="{{ implode(axis) }}"
 		 class="plot"></div>