Fixing Null Reference exception.
Fixing Null Reference exception.

AreYouFreeBusy/AlexaSkillsKit.NET,dg-racing/AlexaSkillsKit.NET,dg-racing/AlexaSkillsKit.NET,AreYouFreeBusy/AlexaSkillsKit.NET,dg-racing/AlexaSkillsKit.NET,AreYouFreeBusy/AlexaSkillsKit.NET