Remove duplication.
diff --git a/Doc/library/email.mime.rst b/Doc/library/email.mime.rst
index a092feb..78fdc76 100644
--- a/Doc/library/email.mime.rst
+++ b/Doc/library/email.mime.rst
@@ -196,6 +196,6 @@
 
    .. versionchanged:: 2.4
       The previously deprecated *_encoding* argument has been removed.  Content
-      Transfer Encoding now happens happens implicitly based on the *_charset*
+      Transfer Encoding now happens implicitly based on the *_charset*
       argument.