WCPS doesn't consider axis labels in scale operation

[Dimitar Misev]

These two queries produce different results, even though just the order of the axes is changed:

for c in ( mr )
return encode(
 scale(c, x:"CRS:1"(0:749), y:"CRS:1"(0:499))
, "png")

and

for c in ( mr )
return encode(
 scale(c, y:"CRS:1"(0:499), x:"CRS:1"(0:749))
, "png")