Make SetCacheHeaders protected virtual, and add no-store to the header

Resolves #1920

Author: exyi

src/Framework/Framework/Runtime/DefaultOutputRenderer.cs

@@ -136,9 +136,9 @@ public virtual async Task RenderPlainTextResponse(IHttpContext context, string t
             await context.Response.WriteAsync(text);
         }
 
-        private static void SetCacheHeaders(IHttpContext context)
+        protected virtual void SetCacheHeaders(IHttpContext context)
         {
-            context.Response.Headers["Cache-Control"] = "no-cache";
+            context.Response.Headers["Cache-Control"] = "no-cache, no-store";
             context.Response.Headers["Pragma"] = "no-cache";
             context.Response.Headers["Expires"] = "-1";
         }