Remove unused variable in static constructors
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs
index 5d56722..56d7e36 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs
@@ -346,7 +346,7 @@
       }
     }
     static OptionsMessage() {
-      pbd::FileDescriptor descriptor = global::Google.ProtocolBuffers.TestProtos.UnitTestCSharpOptionsProtoFile.Descriptor;
+      object.ReferenceEquals(global::Google.ProtocolBuffers.TestProtos.UnitTestCSharpOptionsProtoFile.Descriptor, null);
     }
   }