Missing CUDD derefs.

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@529 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/prism/NondetModelChecker.java

@@ -1608,9 +1608,9 @@ public class NondetModelChecker implements ModelChecker
 				}
 			}
 			catch (PrismException e) {
-				throw e;
 				JDD.Deref(inf);
 				JDD.Deref(maybe);
+				throw e;
 			}
 		}