Using mockito to mock interface with @ObjectiveCName results in failure

This used to work in 2.0.0, but broke sometime between then in 2.0.4

if one has something like

```java
@ObjectiveCName("OMGFoo")
public interface Foo {
void doSomething();
}
```

and then
```java
org.mockito.Mockito.mock(Foo.class)
```

it will blow up with

```
4) throwsOnServerError(omg.bbq.FooTest)
java.lang.IllegalArgumentException: interface omg.bbq.Foo is not visible from class loader
at 0x0000000107090fb8 java.lang.reflect.Proxy.getProxyClass0() + 1777
at 0x0000000107091156 java.lang.reflect.Proxy.newProxyInstance() + 45
at 0x000000010750181d org.mockito.internal.util.MockUtil.createMock() + 65
at 0x00000001074e22ad org.mockito.internal.MockitoCore.mock() + 131
at 0x0000000106dc9590 com.squareup.shared.catalog.sync.WriteMessageTest.setup() + 144
at 0x00000001072e80cd java.lang.reflect.Method.invoke:object:() + 22
```

Observed this in 2.0.4 and 2.0.5.