Revert "fix: Disable imagick preview providers"

This reverts commit 706fe8f.

Signed-off-by: Benjamin Gaussorgues <benjamin.gaussorgues@nextcloud.com>

Author: Altahrim

lib/private/Preview/IMagickSupport.php

@@ -24,12 +24,10 @@ public function __construct(ICacheFactory $cacheFactory) {
 	}
 
 	public function hasExtension(): bool {
-		return false;
 		return !is_null($this->imagick);
 	}
 
 	public function supportsFormat(string $format): bool {
-		return false;
 		if (is_null($this->imagick)) {
 			return false;
 		}