Check whether the send side is not idle, not the recv side (#313)

* Check whether the send side is not idle, not the recv side
* Ensure sure we're handling window updates for the right side
* Add failing test

src/proto/streams/streams.rs

@@ -394,8 +394,7 @@ where
                 );
             } else {
                 me.actions
-                    .recv
-                    .ensure_not_idle(id)
+                    .ensure_not_idle(me.counts.peer(), id)
                     .map_err(RecvError::Connection)?;
             }
         }