title: Firebase Storage keeps replacing image when uploading
body: <p>I am trying to upload 2 images at once and get the DownloadURL to go to the Firebase Database but the second Image function keeps replacing the first one so when I click on the downloadURL for either the first or second it will only grab the second Image. This is my code.</p>
  
  <pre><code>@IBAction func upload(_ sender: Any) {
  
  
      let storageRef = Storage.storage().reference().child("images/\(NSUUID().uuidString)/image.png")
      if let uploadData = UIImagePNGRepresentation(self.myImageView1.image!){
      storageRef.putData(uploadData, metadata: nil, completion: { (metadata, error) in
  
  
  
          let storageRef2 = Storage.storage().reference().child("images2/\(NSUUID().uuidString)/image2.png")
          if let uploadData2 = UIImagePNGRepresentation(self.myImageView2.image!){
          storageRef2.putData(uploadData2, metadata: nil, completion: { (metadata, error) in
  
  
  
                  if error != nil {
                          print("error")
                          return
  
                      } else {
                          let downloadURL = metadata?.downloadURL()?.absoluteString
                          let downloadURL2 = metadata?.downloadURL()?.absoluteString
  
                          self.ref?.child("Posts").childByAutoId().setValue(["Title": self.titleText.text, "Subtitle": self.subtitleText.text, "Article": self.articleText.text, "Author": self.authorText.text, "Date": self.dateText.text, "Tags": self.tagsText.text, "PostType": self.postType.text, "PostStyle": self.postStyle.text, "PostSize": self.postSize.text, "Download URL": (downloadURL), "Download URL 2": (downloadURL2)])
  
              }
  </code></pre>