clear script cache before revalidation, otherwise a script change in the edit dialog does not work

src/main/java/ninja/javafx/smartcsv/validation/Validator.java

@@ -252,4 +252,8 @@ public class Validator {
         }
         return result;
     }
+
+    public void clearScriptCache() {
+        scriptCache.clear();
+    }
 }