sticky unit tooltip if pressing modifier key while hovering over a unit

[frozn]

If you are hovering over a unit, press e.g. shortly the ALT key, and then move your mouse out of the unit, the tooltip doesn't fade out. tested it under retail 10.2.7.

I nailed it down to the following section:

https://github.com/RaiderIO/raiderio-addon/blob/3cf78b53397f70b04cf14b792c1055756eedcf51/core.lua#L5701-L5709

Calling SetUnit() here will make the tooltip sticky.