Eliminate more redundant item tags in SRGS XML.

src/GF/Speech/PrSRGS.hs

@@ -146,5 +146,8 @@ optimizeSRGS = bottomUpXML f
   where f (Tag "item" [] [x@(Tag "item" _ _)]) = x
         f (Tag "item" [] [x@(Tag "one-of" _ _)]) = x
         f (Tag "item" as [Tag "item" [] xs]) = Tag "item" as xs
+        f (Tag "item" as xs) = Tag "item" as (map g xs)
+           where g (Tag "item" [] [x@(ETag "ruleref" _)]) = x
+                 g x = x
         f (Tag "one-of" [] [x]) = x
         f x = x