cleaning

deltachat-ios/Helper/ThumbnailCache.swift

@@ -12,12 +12,11 @@ class ThumbnailCache {
     }()
 
     func storeImage(image: UIImage, key: String){
-        // cache.setObject(image, forKey: NSString(string: key))
+        cache.setObject(image, forKey: NSString(string: key))
     }
 
     func restoreImage(key: String) -> UIImage? {
-        return nil
-        //     return cache.object(forKey: NSString(string: key))
+        return cache.object(forKey: NSString(string: key))
     }
 
     func clearCache() {