Update Doc/library/shutil.rst

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

Author: him2him2

Doc/library/shutil.rst

@@ -545,7 +545,7 @@ instead of 64 KiB) and a :func:`memoryview`-based variant of
 efficient method, supports copy-on-write, and preserves metadata.
 
 If the fast-copy operation fails and no data was written in the destination
-file then shutil will silently fall back on using less efficient
+file then shutil will silently fall back to less efficient
 :func:`copyfileobj` function internally.
 
 .. versionchanged:: 3.8