KT-499 allow class object in static inner classes

like this:

===
class A {
    class object {
        class B {
            class object { }
        }
    }
}
===

compiler/testData/checkerWithErrorTypes/quick/InnerClassClassObject.jet

@@ -5,3 +5,16 @@ class A {
         <!CLASS_OBJECT_NOT_ALLOWED!>class object { }<!>
     }
 }
+
+class B {
+    class object {
+        class B {
+            class object {
+                class C {
+                    class object { }
+                }
+            }
+        }
+    }
+}
+