turn on HandleMethodNotAllowed when using NoMethod gin-gonic#2871 (gi…

…n-gonic#2872)

(cherry picked from commit d6534cc)

gin.go

@@ -249,8 +249,9 @@ func (engine *Engine) NoRoute(handlers ...HandlerFunc) {
 	engine.rebuild404Handlers()
 }
 
-// NoMethod sets the handlers called when... TODO.
+// NoMethod sets the handlers called when NoMethod.
 func (engine *Engine) NoMethod(handlers ...HandlerFunc) {
+	engine.HandleMethodNotAllowed = true
 	engine.noMethod = handlers
 	engine.rebuild405Handlers()
 }