Bumping .NET assembly version number before 5.14.3 release as there were changes

Source commit: 756215608d1c0062994c847fdeb72dc6d1dd0529

dotnet/properties/AssemblyInfo.cs

@@ -35,7 +35,7 @@ namespace WinSCP
     {
         public const string UndefinedProductVersion = "9.9.9.9";
 
-        public const string Version = "1.6.1.0";
+        public const string Version = "1.6.2.0";
         public const string ProductVersion = "5.14.3.0";
     }
 }