bpo-31672: doc: Remove one sentence from library/string.rst (GH-3990)

methane · web-flow · commit 073150db3940 · 2017-10-14T21:22:41.000+09:00
This sentence is removed while backporting to 3.6 branch. See #3982 (comment)
diff --git a/Doc/library/string.rst b/Doc/library/string.rst
@@ -765,7 +765,7 @@ attributes:
 
      While *flags* is kept to ``re.IGNORECASE`` for backward compatibility,
      you can override it to ``0`` or ``re.IGNORECASE | re.ASCII`` when
-     subclassing.  It's simple way to avoid unexpected match like above example.
+     subclassing.
 
   .. versionchanged:: 3.7
      *braceidpattern* can be used to define separate patterns used inside and
