Improve fix instructions if other device is already running QuickDrop

QuickDropiOS/ShareViewModel.swift

@@ -47,7 +47,7 @@ class SendModel: ObservableObject, OutboundAppDelegate {
     
     func connectionFailed(with error: any Error) {
         
-        ErrorAlertHandler.shared.showErrorAlert(for: selectedDevice?.name ?? "?", error: error)
+        ErrorAlertHandler.shared.showErrorAlert(for: selectedDevice?.name ?? "?", error: error, isQuickDropPeer: selectedDevice?.isQuickDropPeer ?? false)
         
         progressValue = nil
         selectedDevice = nil

QuickDropiOS/View/FilePicker.swift

@@ -70,6 +70,8 @@ struct SendPickerButton<Label: View>: View {
                 selectedPhotoItems = []
             } catch {
                 log("Could not fetch photo URLs: \(error)")
+                onResult(nil, nil)   // let the caller dismiss the "preparing" it opened on `onPrepare`
+                selectedPhotoItems = []
             }
         }
     }