Update UrlHelper.swift

Author: swiftuiux

Sources/async-http-client/proxy/helper/UrlHelper.swift

@@ -13,7 +13,7 @@ import retry_policy_service
 ///   - url:  url
 ///   - query: An array of name-value pairs
 /// - Returns: A value that identifies the location of a resource
-public func append(_ url: URL,with query : Http.Query? = nil) throws -> URL{
+func append(_ url: URL,with query : Http.Query? = nil) throws -> URL{
 
     guard var components = URLComponents(url: url, resolvingAgainstBaseURL: true)else{
         throw URLError(.badURL)