revert local change that should never have been committed

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@959175 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/Execute.java

@@ -498,6 +498,7 @@ public class Execute {
                 watchdog.stop();
             }
             streamHandler.stop();
+            closeStreams(process);
 
             if (watchdog != null) {
                 watchdog.checkException();