java: scripting: fix bug in removing model from map

found by PMD

Change-Id: I4bd35dd30f6c77aad96932216d8459b812004a88

scripting/java/com/sun/star/script/framework/io/XStorageHelper.java

@@ -181,7 +181,7 @@ public class XStorageHelper implements XEventListener {
 
         if (model != null) {
             LogUtils.DEBUG(" Disposing doc " + model.getURL());
-            modelMap.remove(model);
+            modelMap.remove(PathUtils.getOidForModel(model));
         }
     }