Updated lib, fixed icon_url in .showembed

src/NadekoBot/Common/SmartText/SmartTextEmbedAuthor.cs

@@ -1,5 +1,6 @@
 #nullable disable
 using Newtonsoft.Json;
+using System.Text.Json.Serialization;
 
 namespace NadekoBot;
 
@@ -8,6 +9,7 @@ public class SmartTextEmbedAuthor
     public string Name { get; set; }
 
     [JsonProperty("icon_url")]
+    [JsonPropertyName("icon_url")]
     public string IconUrl { get; set; }
 
     public string Url { get; set; }