1.x Use IntelliJ IDE friendly assertion failure message (#5258)

* Test Intellij formatting fix

* Fix test subscriber test case

Author: mtiidla

src/main/java/rx/observers/TestSubscriber.java

@@ -337,11 +337,11 @@ private void assertItem(T expected, int i) {
         if (expected == null) {
             // check for null equality
             if (actual != null) {
-                assertionError("Value at index: " + i + " expected to be [null] but was: [" + actual + "]\n");
+                assertionError("Value at index: " + i + " expected: [null] but was: [" + actual + "]\n");
             }
         } else if (!expected.equals(actual)) {
             assertionError("Value at index: " + i
-                    + " expected to be [" + expected + "] (" + expected.getClass().getSimpleName()
+                    + " expected: [" + expected + "] (" + expected.getClass().getSimpleName()
                     + ") but was: [" + actual + "] (" + (actual != null ? actual.getClass().getSimpleName() : "null") + ")\n");
 
         }

src/test/java/rx/observers/TestSubscriberTest.java

@@ -72,7 +72,7 @@ public void testAssertNotMatchValue() {
         oi.subscribe(o);
 
         thrown.expect(AssertionError.class);
-        thrown.expectMessage("Value at index: 1 expected to be [3] (Integer) but was: [2] (Integer)");
+        thrown.expectMessage("Value at index: 1 expected: [3] (Integer) but was: [2] (Integer)");
 
 
         o.assertReceivedOnNext(Arrays.asList(1, 3));