Remove redundant reflection-based default maxBackoffMs test

The testRepeatRetryAfterRateLimit test already covers default backoff
behavior (7 requests = 32s max) through observable retry count.

Author: jeffreyparker

duo-client/src/test/java/com/duosecurity/client/HttpRateLimitRetryTest.java

@@ -209,17 +209,6 @@ public Call answer(InvocationOnMock invocationOnMock) throws Throwable {
         assertEquals(4000L + RANDOM_INT, (long) sleepTimes.get(2));
     }
 
-    @Test
-    public void testDefaultMaxBackoffIsUsedWhenNotSpecified() throws Exception {
-        Http defaultHttp = new Http.HttpBuilder("GET", "example.test", "/foo/bar").build();
-
-        Field maxBackoffField = Http.class.getDeclaredField("maxBackoffMs");
-        maxBackoffField.setAccessible(true);
-        long actualMaxBackoff = (long) maxBackoffField.get(defaultHttp);
-
-        assertEquals(Http.MAX_BACKOFF_MS, actualMaxBackoff);
-    }
-
     @Test(expected = IllegalArgumentException.class)
     public void testMaxBackoffNegativeThrows() {
         new Http.HttpBuilder("GET", "example.test", "/foo/bar")