explicitly cast StringBuffer to Object so that the "right" append
method gets chosen. This ensures that a JDK 1.4 compiled Ant can be
run on JDK 1.2. Well, makes it more likely.
PR: 22705
git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@275142 13f79535-47bb-0310-9956-ffa450edef68