review: remove unnecessary protected:

Signed-off-by: mathetake <[email protected]>

Author: mathetake

include/proxy-wasm/context.h

@@ -406,7 +406,6 @@ class DeferAfterCallActions {
   DeferAfterCallActions(ContextBase *context) : context_(context) {}
   ~DeferAfterCallActions();
 
-protected:
 private:
   ContextBase *const context_;
 };