Typo fix - "mesasge" should be "message" (GH-22498)

* Correct at 2 places in email module
(cherry picked from commit 9cd01ec)

Co-authored-by: Hansraj Das <[email protected]>

Author: miss-islington

Lib/email/message.py

@@ -141,7 +141,7 @@ def as_string(self, unixfrom=False, maxheaderlen=0, policy=None):
         header.  For backward compatibility reasons, if maxheaderlen is
         not specified it defaults to 0, so you must override it explicitly
         if you want a different maxheaderlen.  'policy' is passed to the
-        Generator instance used to serialize the mesasge; if it is not
+        Generator instance used to serialize the message; if it is not
         specified the policy associated with the message instance is used.
 
         If the message object contains binary data that is not encoded
@@ -958,7 +958,7 @@ def as_string(self, unixfrom=False, maxheaderlen=None, policy=None):
         header.  maxheaderlen is retained for backward compatibility with the
         base Message class, but defaults to None, meaning that the policy value
         for max_line_length controls the header maximum length.  'policy' is
-        passed to the Generator instance used to serialize the mesasge; if it
+        passed to the Generator instance used to serialize the message; if it
         is not specified the policy associated with the message instance is
         used.
         """