bpo-33892: Doc: Use gender neutral words (GH-7770)

(cherry picked from commit 5092439c2cb32112a5869b138011d38491db90a9)

Co-authored-by: Andrés Delfino <adelfino@gmail.com>
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst
index 4af75a1..627eb7d 100644
--- a/Doc/library/optparse.rst
+++ b/Doc/library/optparse.rst
@@ -1679,7 +1679,7 @@
 problems with the option or its argument(s).  :mod:`optparse` catches this and
 terminates the program, printing the error message you supply to stderr.  Your
 message should be clear, concise, accurate, and mention the option at fault.
-Otherwise, the user will have a hard time figuring out what he did wrong.
+Otherwise, the user will have a hard time figuring out what they did wrong.
 
 
 .. _optparse-callback-example-1: