Require HTTPS for WebDAV sync

Services/CloudSyncService.cs

@@ -36,9 +36,9 @@ public sealed class CloudSyncService
     private static Uri BuildTarget(string endpoint)
     {
         if (!Uri.TryCreate(endpoint?.Trim(), UriKind.Absolute, out var uri)
-            || (uri.Scheme != Uri.UriSchemeHttps && uri.Scheme != Uri.UriSchemeHttp))
+            || uri.Scheme != Uri.UriSchemeHttps)
         {
-            throw new ArgumentException("Inserisci un indirizzo WebDAV http o https valido.");
+            throw new ArgumentException("Inserisci un indirizzo WebDAV HTTPS valido.");
         }
         return uri.AbsolutePath.EndsWith(".zip", StringComparison.OrdinalIgnoreCase)
             ? uri