Fix json compact (2dust#9246)

Author: DHR60

v2rayN/ServiceLib/Common/JsonUtils.cs

@@ -17,13 +17,27 @@ public class JsonUtils
         Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
     };
 
+    private static readonly JsonSerializerOptions _defaultSerializeNoIndentedOptions = new()
+    {
+        WriteIndented = false,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
+    };
+
     private static readonly JsonSerializerOptions _nullValueSerializeOptions = new()
     {
         WriteIndented = true,
         DefaultIgnoreCondition = JsonIgnoreCondition.Never,
         Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
     };
 
+    private static readonly JsonSerializerOptions _nullValueSerializeNoIndentedOptions = new()
+    {
+        WriteIndented = false,
+        DefaultIgnoreCondition = JsonIgnoreCondition.Never,
+        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
+    };
+
     private static readonly JsonDocumentOptions _defaultDocumentOptions = new()
     {
         CommentHandling = JsonCommentHandling.Skip
@@ -104,7 +118,13 @@ public static string Serialize(object? obj, bool indented = true, bool nullValue
             {
                 return result;
             }
-            var options = nullValue ? _nullValueSerializeOptions : _defaultSerializeOptions;
+            var options = (nullValue, indented) switch
+            {
+                (true, true) => _nullValueSerializeOptions,
+                (true, false) => _nullValueSerializeNoIndentedOptions,
+                (false, true) => _defaultSerializeOptions,
+                _ => _defaultSerializeNoIndentedOptions
+            };
             result = JsonSerializer.Serialize(obj, options);
         }
         catch (Exception ex)