Fixes (see commit description)

- Fix issue caused by merge
- Improve icons in onboarding
- Use onboarding's pairing file step properly

AltStore/Operations/OperationError.swift

@@ -163,5 +163,4 @@ extension MinimuxerError: LocalizedError {
     fileprivate func setArgument(name: String) -> String {
         return String(format: NSLocalizedString("Cannot set %@ on the device.", comment: ""), name)
     }
-    return error as! OperationError
 }