Back porting changeset db302b88fdb6 to 3.4 branch, which fixed multiple documentation typos.

Related Issues:

#issue21528
#issue24453
diff --git a/Doc/howto/sockets.rst b/Doc/howto/sockets.rst
index d5aff90..04394d4 100644
--- a/Doc/howto/sockets.rst
+++ b/Doc/howto/sockets.rst
@@ -234,7 +234,7 @@
 following message. You'll need to put that aside and hold onto it, until it's
 needed.
 
-Prefixing the message with it's length (say, as 5 numeric characters) gets more
+Prefixing the message with its length (say, as 5 numeric characters) gets more
 complex, because (believe it or not), you may not get all 5 characters in one
 ``recv``. In playing around, you'll get away with it; but in high network loads,
 your code will very quickly break unless you use two ``recv`` loops - the first