Fix issue with SVG import of viewBox with x & y that are non-zero

When importing an SVG file that has a viewBox with an x or y component then the content is not correctly positioned in the viewport. This change correctly positions the content.

e.g.
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="6.287879in" height="3.750000in" version="1.1" viewBox="150.000000 85.500000 830.000000 495.000000">