removed unused variable

Author: bachuv

client/src/test/java/com/microsoft/durabletask/TaskEntityTest.java

@@ -250,7 +250,6 @@ void reflectionDispatch_methodWithReturnValue() throws Exception {
     @Test
     void reflectionDispatch_caseInsensitive() throws Exception {
         CounterEntity entity = new CounterEntity();
-        DataConverter converter = new JacksonDataConverter();
 
         // Method is "add" but call with "ADD"
         TaskEntityOperation addOp = createOperation("ADD", 10);