Issue title: BO - New employee page - Help Card is not displayed in sidebar
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#### Describe the bug

In the BO => Team => Employees Tab => Add anew employee page, When we click on the button 'help', the sidebar is not opened in the same page, it redirect us to `shop.com/admin-dev/index.php/common/sidebar/https%253A%252F%252Fhelp.prestashop.com%252Fen%252Fdoc%252FAdminEmployees%253Fversion%253D116.69.203.115%2526country%253Den/Help?_token=pKbqyg0aj7rVlQAJSXFU1rliXcpAEgdxcp-id8R3BWE
`
#### Expected behavior

SideBar opened in the same page

#### Steps to Reproduce

Steps to reproduce the behavior:

1. Go to the BO => Team => Employees Tab => Add anew employee page
2. Click on button 'Help'
3. See error

**Screenshots**

![image](https://user-images.githubusercontent.com/16067358/79221548-4d74aa00-7e56-11ea-8c58-f8a522a76db8.png)


#### Additional information

* PrestaShop version: 177x,1760,1764
* PHP version: 7.2

 Comments: 
 Comment 0: Thanks for opening this issue! We will help you to keep its state consistent
 Comment 1: Related to: https://github.com/PrestaShop/PrestaShop/issues/18279
 Comment 2: Fixed by #18637 
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