Fix form_params usage in Permanent token sendAuthenticatedRequest

[nyroDev]

Using a Permanent Token,
When trying to modify description of a media with multiple lines like that:

$description = 'Line 1
Line 2';
$client->getAssetBankManager()->modifyMedia($mediaId, [
    'description' => $description,
])->wait();

I had the Guzzle error:

[InvalidArgumentException]                                              
"Line 1                                                 
Line 2" is not valid header value.

The reason is simple:
The form_params is sent to headers when creating Requests...

The fix simply remove the setting from the header and everything is working correctly for me.