bugfix: correct service include in ruby compiler

Change on 2015/01/06 by temiola <temiola@google.com>
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=83393999

src/compiler/ruby_generator.cc

@@ -100,7 +100,7 @@ void PrintService(const ServiceDescriptor* service, const string& package,
   // Write the indented class body.
   out->Indent();
   out->Print("\n");
-  out->Print("include GRPC::Generic::Service\n");
+  out->Print("include GRPC::GenericService\n");
   out->Print("\n");
   out->Print("self.marshal_class_method = :encode\n");
   out->Print("self.unmarshal_class_method = :decode\n");