use _isServer flag to determine whether __path__ should be noop

src/entries/web-runtime.js

@@ -1,11 +1,11 @@
 import Vue from 'core/index'
+import config from 'core/config'
 import { createPatchFunction } from 'core/vdom/patch'
 import * as nodeOps from 'web/runtime/node-ops'
 import platformDirectives from 'web/runtime/directives/index'
 import baseModules from 'core/vdom/modules/index'
 import platformModules from 'web/runtime/modules/index'
 import { query, isUnknownElement, isReservedTag } from 'web/util/index'
-import { inBrowser } from 'core/util/env'
 import { noop } from 'core/util/index'
 
 // install platform specific utils
@@ -17,9 +17,9 @@ Vue.options.directives = platformDirectives
 
 // install platform patch function
 const modules = baseModules.concat(platformModules)
-Vue.prototype.__patch__ = inBrowser
-  ? createPatchFunction({ nodeOps, modules })
-  : noop
+Vue.prototype.__patch__ = config._isServer
+  ? noop
+  : createPatchFunction({ nodeOps, modules })
 
 // wrap mount
 Vue.prototype.$mount = function (el) {