Fix text spill on Flight description

[jreyesr]

When the description of a Flight contains too much text in a single line, it spills over the border of the card.

Issue is especially pronounced on narrower screens, since there's less space for each card:

Edit: it also happens on the Flight details screen:

[jreyesr]

This bug is most likely confirmed to be caused by the use of <span style="white-space: pre;">. Use of pre-wrap instead should fix it.