Remove PUT restriction for all columns/single row

Fixes https://github.com/PostgREST/postgrest/issues/1452.

The single row restriction can be lifted because the
PUT will consider only the first object of the array.

src/PostgREST/Types.hs

@@ -309,9 +309,8 @@ data PayloadJSON =
   ProcessedJSON {
     -- | This is the raw ByteString that comes from the request body.
     -- We cache this instead of an Aeson Value because it was detected that for large payloads the encoding
-    -- had high memory usage, see #1005 for more details
+    -- had high memory usage, see https://github.com/PostgREST/postgrest/pull/1005 for more details
     pjRaw  :: BL.ByteString
-  , pjType :: PJType
     -- | Keys of the object or if it's an array these keys are guaranteed to be the same across all its objects
   , pjKeys :: S.Set Text
   }|