Add option to disable DRM decryption

src/invidious.cr

@@ -78,10 +78,12 @@ REDDIT_URL = URI.parse("https://www.reddit.com")
 LOGIN_URL  = URI.parse("https://accounts.google.com")
 
 decrypt_function = [] of {name: String, value: Int32}
-spawn do
+if CONFIG.decrypt_drm
+  spawn do
     update_decrypt_function do |function|
       decrypt_function = function
     end
+  end
 end
 
 proxies = PROXY_LIST

src/invidious/helpers/helpers.cr

@@ -16,6 +16,10 @@ class Config
     hmac_key:     String?,
     full_refresh: Bool,
     domain:       String?,
+    decrypt_drm:  {
+      type:    Bool?,
+      default: true,
+    },
   })
 end