Steps to reproduce:

1. Setup SAML and enable SCIM
2. Send http request to api_scim.php. For example: 

# 
GET http://hostname/branchname/ui/api_scim.php/Groups HTTP/1.1
Authorization: Bearer 5883b54831e2721958bd7db7e1c153889adcc4c6fffd988843e09a211939b320
Content-Type: application/json

### 

Result:
Response with 500 error code and error message.

{
  "schemas": [
    "urn:ietf:params:scim:api:messages:2.0:Error"
  ],
  "detail": "Class name must be a valid object or a string",
  "status": 500
} 

Expected:
There should be 200 code response with a valid schema.

Error occurs because CLocalApiClient()->authenticate() method has changed.

Now token authentication goes through CUser()->checkAuthentication(), but it is not available in SCIM registry factory.