Fix NullConverter test

All Null inputs should be allowed.

Author: hinerm

src/test/java/org/scijava/convert/ConverterTest.java

@@ -61,7 +61,7 @@ public void testNullConverter() {
 		final NullConverter nc = new NullConverter();
 		assertFalse(nc.canConvert(Object.class, Object.class));
 		assertFalse(nc.canConvert(Object.class, (Type) Object.class));
-		assertFalse(nc.canConvert((Class<?>) null, Object.class));
+		assertTrue(nc.canConvert((Class<?>) null, Object.class));
 		assertTrue(nc.canConvert((Object) null, Object.class));
 		assertTrue(nc.canConvert((ConverterTest) null, ArrayList.class));
 		assertNull(nc.convert((Object) null, Object.class));