Fixed bug from type error in priority_queue:delete_value/2.

src/priority_queue.erl

@@ -61,7 +61,7 @@ find_value(Val, Queue) ->
     end.
 
 delete_value(Val, Queue) ->
-    map_values(fun(Vs) -> [ V || V <- Vs, V =/= Val ] end, Queue).
+    gb_trees:map(fun(_Key, Vs) -> [ V || V <- Vs, V =/= Val ] end, Queue).
 
 take_value(Val, Queue) ->
     case [ {P, V, Vs} || {P, Vs} <- to_orddict(Queue), V <- Vs, V == Val ] of