crash when moved with windock active

[slippycheeze]

I use windock to manage window layout; it'll automatically "snap" the position and size of windows when they are moved. If that is active it triggers squalr to crash repeatably for me; nothing other than having "docking" active is needed.

I doubt it is needed, but my windock configuration is exported to a file here: windock.json

repro steps:

1. disable windock docking
2. launch squalr 2.3.12
3. move the window
4. enable windock docking
5. move the window (seems to trigger on left-mouse-down, or the first pixel of movement)
6. <crashy!~>