It is just a quick fix for the tooltips in the graph editor, it replaces:
- "F-curve modifiers are disabled" with "Enable F-Curve modifiers"
- "F-curve is visible in graph editor for editing" with "F-Curve visibility in Graph Editor".
However, "git diff" doesn't seem to take into account the files in "blender/release/datafiles/locale/po/" I don't really know if it should.