Add one more exclude for file-leak-detector

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1898384 13f79535-47bb-0310-9956-ffa450edef68

file-leak-detector.exclude

@@ -56,6 +56,7 @@ sun.util.resources.LocaleData.getBundle
 sun.util.LocaleServiceProviderPool.<init>
 sun.util.calendar.LocalGregorianCalendar.getLocalGregorianCalendar
 sun.net.www.protocol.jar.JarURLConnection.getInputStream
+sun.misc.URLClassPath$JarLoader.ensureOpen
 sun.text.normalizer.ICUData.getStream
 sun.font.T2KFontScaler.initNativeScaler
 sun.font.SunFontManager.loadFonts