Bumping .NET assembly version number before 5.20.3 release as there were changes

Source commit: 1d155da8e274f98304200a9309a56d10905ce8f4

dotnet/properties/AssemblyInfo.cs

@@ -35,7 +35,7 @@ namespace WinSCP
     {
         public const string UndefinedProductVersion = "9.9.9.9";
 
-        public const string Version = "1.10.0.0";
+        public const string Version = "1.11.0.0";
         public const string ProductVersion = "5.20.3.0";
     }
 }