accidentally removed some error checking

h2/src/main/org/h2/expression/Aggregate.java

@@ -372,6 +372,9 @@ public class Aggregate extends Expression {
                 DbException.throwInternalError("type=" + type);
             }
         }
+        if (!select.isCurrentGroup()) {    
+            throw DbException.get(ErrorCode.INVALID_USE_OF_AGGREGATE_FUNCTION_1, getSQL());    
+        }
         AggregateData data = (AggregateData)select.getCurrentGroupExprData(this);
         if (data == null) {
             data = AggregateData.create(type);