Fixed spelling error in method

But, really, the goal here is just to commit a change so that the next merge request will maintain the histories of `Program` and the new minimal hosting model.

Author: JeremyCaney

OnTopic.AspNetCore.Mvc.Host/Program.cs

@@ -11,7 +11,7 @@ namespace OnTopic.AspNetCore.Mvc.Host {
   | CLASS: PROGRAM
   \---------------------------------------------------------------------------------------------------------------------------*/
   /// <summary>
-  ///   The <see cref="Program"/> class—and it's <see cref="Program.Main(String[])"/> method—represent the entry point into the
+  ///   The <see cref="Program"/> class—and its <see cref="Program.Main(String[])"/> method—represent the entry point into the
   ///   ASP.NET Core web application.
   /// </summary>
   [ExcludeFromCodeCoverage]