Javascript errors on login page

[sharkykh]

Describe the bug
Doesn't affect usability, just need to fix some stuff to not run on the /login route, like we do elsewhere.

To Reproduce
Steps to reproduce the behavior:

1. Set username and password for the Web UI
2. Log out of the Web UI
3. See console errors

Medusa:

• OS: Windows 7 x64
• Branch: vueify/header (probably applies to develop)
• Commit: ef0e511

Logs:

15:26:14.066 api.js:8 Uncaught TypeError: Cannot read property 'replace' of undefined
    at api.js:8
(anonymous) @ api.js:8
15:26:14.243 store.js:501 Uncaught TypeError: Cannot read property 'replace' of undefined
    at websocketUrl (store.js:501)
    at store.js:504
websocketUrl @ store.js:501
(anonymous) @ store.js:504
15:26:14.259 router.js:11 Uncaught TypeError: Cannot read property 'replace' of null
    at router.js:11
(anonymous) @ router.js:11
15:26:14.260 localhost/:1528 Loading Vue with router since window.app is missing.
15:26:14.263 vue.js:597 [Vue warn]: Error in created hook: "TypeError: Cannot set property 'onmessage' of undefined"

(found in <Root>)
warn @ vue.js:597
logError @ vue.js:1739
globalHandleError @ vue.js:1734
handleError @ vue.js:1723
callHook @ vue.js:2923
Vue._init @ vue.js:4617
Vue @ vue.js:4716
(anonymous) @ localhost/:1529
15:26:14.263 vue.js:1743 TypeError: Cannot set property 'onmessage' of undefined
    at Vue.created (localhost/:1483)
    at callHook (vue.js:2921)
    at Vue._init (vue.js:4617)
    at new Vue (vue.js:4716)
    at localhost/:1529
logError @ vue.js:1743
globalHandleError @ vue.js:1734
handleError @ vue.js:1723
callHook @ vue.js:2923
Vue._init @ vue.js:4617
Vue @ vue.js:4716
(anonymous) @ localhost/:1529
15:26:14.549 vue.js:8553 You are running Vue in development mode.
Make sure to turn on production mode when deploying for production.
See more tips at https://vuejs.org/guide/deployment.html
15:26:14.607 chrome-extension://nhdogjmejiglipccpnnnanhbledajbpd/build/backend.js:1  vue-devtools  Detected Vue v2.5.16