Ultimate Member - Social Login 2.5.6

* Fixed: PHP warnings
* Tweak: Template overwrite versioning

* Added: Default Profile Photo for Facebook & Discord
* Fixed: Previous page redirection by 'redirect_to' argument
* Deprecated: Get rid VK social connect. See [details](https://github.com/hybridauth/hybridauth/releases/tag/v3.8.2)

* Fixed: Return URL of the Social Networks with single callback URL
* Fixed: Linking social account when logged-in
* Fixed: Time account connected in the Account > Social Tab.
* Added: Remove synced data on disconnecting Social Accounts
* Added: New icons to support other Social Network providers
* New: Debug logging tool. Please read: Social Login 2.3 Setup - Ultimate Member
* New: TwitchTV and Discord settings. Please read the Setup: Social Login 2.3 Setup - Ultimate Member
* Deprecated: Instagram settings has been removed.