Fix #2020

[shuen4]

originally fixed in 5161f2e but broken after 88c4e68

details

when executing Terraria.ModLoader.Engine.FNAFixes.Init(), Microsoft.Xna.Framework.SDL2_FNAPlatform is not yet initialized

execution routine:

// ...
FNAFixes.Init();
// ...
new Main();
base(); // will initialize FNAPlatform and overwrite previously set SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS value

[Chicken-Bones]

Hi, yes, I noticed this recently, but I was considering leaving it in the same place and setting it using HINT_PRIORITY_OVERRIDE

[shuen4]

changed to use SDL_SetHintWithPriority and SDL_HINT_OVERRIDE in 17b0802