Actually correct mypy line

CODING_STYLE.rst

@@ -28,7 +28,7 @@ primarily by people, not by computers. Do not reorder the code or add weird
 comments just to make mypy happy. Instead, just add something like ``# fuck
 mypy vX.Y.Z`` to notify the programmer that it disagrees. In this case, always
 add the version of broken type checker. (Comments like ``# mypy
-ignore[import]`` are distracting and may be too cryptic for people.)
+ignore=import`` are distracting and may be too cryptic for people.)
 
 There is no need to add hints to everything. Do not add superfluous hints, like
 in ``count: int = 0``. Again, think of the people reading the code, not the