Remove mistaken duplicate line

Author: nolanlawson

index.bs

@@ -3024,8 +3024,6 @@ To <dfn>add or put</dfn> with |handle|, |value|, |key|, and |no-overwrite flag|,
 
     1. If |r| is "invalid value" or "invalid type", [=exception/throw=] a "{{DataError}}" {{DOMException}}.
 
-    1. Let |r| is "invalid value" or "invalid type", [=exception/throw=] a "{{DataError}}" {{DOMException}}.
-
     1. Let |key| be |r|.
 
 1. Let |targetRealm| be a user-agent defined [=ECMAScript/Realm=].