Change Icon back to field to maintain backward compatibility

Author: taooceros

Flow.Launcher.Plugin/Result.cs

@@ -50,7 +50,7 @@ public string IcoPath
         /// <summary>
         /// Delegate to Get Image Source
         /// </summary>
-        public IconDelegate Icon { get; set; }
+        public IconDelegate Icon;
 
         /// <summary>
         /// Information for Glyph Icon