Update Migration Guide doc again

cztomczak · cztomczak · commit 8c5842468f65 · 2018-08-28T10:31:17.000+02:00
diff --git a/docs/Migration-guide.md b/docs/Migration-guide.md
@@ -179,7 +179,7 @@ its implementation in `src/dpi_aware_win.pyx`.
 
 This function can sometimes cause app hanging during window resize.
 Call instead the new `WindowUtils`.[UpdateBrowserSize](../api/WindowUtils.md#updatebrowsersize)
-function. Unless you use the `pywin32.py` example, in such case
+function. Except when you use the `pywin32.py` example, in such case
 `WindowUtils.OnSize` must be called.
 See [Issue #464](../../../issues/464) for more details.
 
