Stories with grid layout do not show the entire grid on load

[jmuhlich]

Something broke with the grid layout recently. When a story with a grid is loaded, the OSD viewport zooms to the first image rather than the entire grid. Example where it was noticed:

published location: https://www.cycif.org/data/tnp-2020/osd-crc-case-1-ffpe-cycif
yaml file: https://github.com/labsyspharm/cycif.org/blob/master/_data/config-tnp-2020/crc-case-1-ffpe-cycif.yaml

But the original melanoma triplet data also shows the issue:

https://www.cycif.org/osd-exhibit
https://github.com/labsyspharm/cycif.org/blob/master/_data/config-lin-elife-2018/ex1.yaml