tests: add testcase for #314

This should be fixed by merging #364.

Thanks @tryone144 for pointing out the root cause.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

tests/configs/issue314.conf

@@ -0,0 +1,6 @@
+fading = true
+fade-in-step = 1
+fade-out-step = 0.01
+inactive-opacity = 0
+blur-background = true
+force-win-blend = true