Allow email to be retrieve by SSO ReverseProxy

If REMOTE_EMAIL header is set, use it as user email.
If REVERSE_PROXY_DEFAULT_DOMAIN is set but not REMOTE_EMAIL, use the current construct.

app/Auth/ReverseProxyAuth.php

@@ -43,10 +43,11 @@ class ReverseProxyAuth extends Base implements PreAuthenticationProviderInterfac
     public function authenticate()
     {
         $username = $this->request->getRemoteUser();
+        $email = $this->request->getRemoteEmail();
 
         if (! empty($username)) {
             $userProfile = $this->userCacheDecorator->getByUsername($username);
-            $this->userInfo = new ReverseProxyUserProvider($username, $userProfile ?: array());
+            $this->userInfo = new ReverseProxyUserProvider($username, $email, $userProfile ?: array());
             return true;
         }