Fix redirects not passing the right forum action

Do not use base64 for encoding urls
Fix the call to the redirect action failing.

ForumProvider/elk1.0.php

@@ -42,7 +42,7 @@ public function decodeCookie()
 	*/
 	public function getRedirectURL(string $action, string $wiki_url, bool $do_return = false)
 	{
-		$forum_action = $this->$validRedirectActions[$action];
+		$forum_action = $this->validRedirectActions[$action];
 
 		$forum_url =
 			$this->ForumSettings['boardurl']

ForumProvider/smf2.0.php

@@ -138,13 +138,13 @@ public function decodeCookie()
 	*/
 	public function getRedirectURL(string $action, string $wiki_url, bool $do_return = false)
 	{
-		$forum_action = $this->$validRedirectActions[$action];
+		$forum_action = $this->validRedirectActions[$action];
 
 		$forum_url =
 			$this->ForumSettings['boardurl']
 			. '/index.php?action=' . $forum_action
 			. ';return_hash=' . hash_hmac('sha1', $wiki_url, $this->ForumSettings['image_proxy_secret'])
-			. ';return_to=' . base64_encode($wiki_url);
+			. ';return_to=' . urlencode($wiki_url);
 
 		return (string) $forum_url;
 	}

ForumProvider/smf2.1.php

@@ -37,13 +37,13 @@ public function decodeCookie()
 	*/
 	public function getRedirectURL(string $action, string $wiki_url, bool $do_return = false)
 	{
-		$forum_action = $this->$validRedirectActions[$action];
+		$forum_action = $this->validRedirectActions[$action];
 
 		$forum_url =
 			$this->ForumSettings['boardurl']
 			. '/index.php?action=' . $forum_action
 			. ';return_hash=' . hash_hmac('sha1', $wiki_url, $this->ForumSettings['auth_secret'])
-			. ';return_to=' . base64_encode($wiki_url);
+			. ';return_to=' . urlencode($wiki_url);
 
 		return $forum_url;
 	}

ForumSsoProvider.php

@@ -65,7 +65,7 @@ public function __construct(array $params = [])
         parent::__construct($params);
 
 		// We hand this off for later to be used in our static function calls.
-		$wgForumSessionProviderInstance = &$this;
+		$wgForumSessionProviderInstance = $this;
 
 		// We use MWLogger here as logger seems to get destroyed.  Sets up logging of this extension for debugging purposes.
         $this->MWlogger = \MediaWiki\Logger\LoggerFactory::getInstance('ForumSessionProvider');
@@ -129,7 +129,7 @@ public static function onSpecialPageBeforeExecute($special, $subPage)
 		global $wgForumSessionProviderInstance;
 
 		// Ensure its callable.
-		if (!is_callable($wgForumSessionProviderInstance, 'doRedirect'))
+		if (!is_callable(array($wgForumSessionProviderInstance, 'doRedirect')))
 			return;
 
 		// The case of some of these isn't always consistent with what shows up in the url.