Description:

wxmaxima fails when producing plots using wxplot functions giving this error:

set terminal png picsize 600 400; set zeroaxis;;
"/tmp/maxout11014.gnuplot", line 1: unrecognized terminal option

The problem is wxmaxima setting the terminal to a value that is no longer valid.
gnuplot is who is giving the error. If one runs gnuplot on the output file mentioned above (and attached), it produces the offending message.

Previously, wxmaxima would "set terminal pngcairo"

Additional info:
* package version(s): 18.02.0-1
* config and/or log files etc.


Steps to reproduce:
open wxmaxima and attempt to plot via wxplot functions. i.e.
wxplot2d(%e^(-x^2), [x,-10, 10]);
wxplot3d ( 8 * y + 10 , [x, -2, 2], [y, -2, 2], [z, -8, 8]);