Update Syntax.icl

In clean-compiler-and-rts/6b890e35e78c6cde75947593efd4b7776caf5b0b the restriction was lifted. It appeared that it forgot to copy it to the icl

backend/Builtin/Syntax.icl

@@ -237,8 +237,7 @@ bs_extensible_adt =
 		[ "Extensible algebraic data types are ADTs that can be extended in other modules."
 		, "One module can declare the ADT as extendible by adding the `..` constructor."
 		, "Other modules can then extend it."
-		, "However, extensions can not be exported."
-		, "It is also not possible to derive generic functions for EADTs."
+		, "It is not possible to derive generic functions for EADTs."
 		]
 	, syntax_doc_locations = []
 	, syntax_examples      = map EX