test(WarningsTest): fix for unused_throws

It is unused_throw"s", and we do want that one caught.

Author: xdavidwu

src/test/java/org/javacs/WarningsTest.java

@@ -92,7 +92,7 @@ public void unused() {
         assertThat(errors, hasItem("unused_method(30)")); // private void unusedMutuallyRecursive1() { ... }
         assertThat(errors, hasItem("unused_method(34)")); // private void unusedMutuallyRecursive2() { ... }
         assertThat(errors, not(hasItem("unused_method(38)"))); // private int usedByUnusedVar() { ... }
-        assertThat(errors, not(hasItem("unused_throw(46)"))); // void notActuallyThrown() throws Exception { }
+        assertThat(errors, hasItem("unused_throws(46)")); // void notActuallyThrown() throws Exception { }
     }
 
     @Test