Mojo: Get rid of some EOL whitespace in C++ .tmpl files.

mojo/public/tools/bindings/generators/cpp_templates/interface_stub_declaration.tmpl

 class {{interface.name}}Stub : public mojo::MessageReceiver {
  public:
   explicit {{interface.name}}Stub({{interface.name}}* sink);
-  
+
   virtual bool Accept(mojo::Message* message) MOJO_OVERRIDE;
   virtual bool AcceptWithResponder(mojo::Message* message,
                                    mojo::MessageReceiver* responder)
                                        MOJO_OVERRIDE;
 
  private:
   {{interface.name}}* sink_;
 };