Incorrect Nbr pixels in CreateMapProcessor

[sebr72]

Context

• MapFish print version: 3.30.6

Describe the bug

in method createMapContext (line 150 use of method Math.ceil will round incorrectly up when it is only the dpiRatio imprecision that is rounded up))

How to reproduce

Use localhost:8080 TestPrint to create and get Print for image_layer_test