When 'Show legend' option is active in a pie chart, a lot of space is lost on the right side as can be seen in attached zabbix_pie.png.

I have attached a patch that:

• removes 'Value:' useless label
• moves values next to item names
• centers pie horizontally

After applying this patch, the pie looks like attached zabbix_pie_optimized.png and graph width can be reduced.