e20a242 broke jpgraph on ubuntu 14.04
The following hides the error, and the graphs works again.
[13:56:53] <@laf> spec_: you could try editing ./vendor/amenadiel/jpgraph/src/image/Image.php
[13:57:13] <@laf> line 103
[13:57:18] <@laf> comment it out and see if it works
fix: Update jpgraph source file to remove check for imageantialias() #…