GracePeriod not Graceperiod

(cherry picked from commit 993c69530ed34460800f40ecf8a0b7bc9a2f7d48)

Closes #2462

src/NzbDrone.Core/HealthCheck/HealthCheckFailedEvent.cs

@@ -5,12 +5,12 @@ namespace NzbDrone.Core.HealthCheck
     public class HealthCheckFailedEvent : IEvent
     {
         public HealthCheck HealthCheck { get; private set; }
-        public bool IsInStartupGraceperiod { get; private set; }
+        public bool IsInStartupGracePeriod { get; private set; }
 
-        public HealthCheckFailedEvent(HealthCheck healthCheck, bool isInStartupGraceperiod)
+        public HealthCheckFailedEvent(HealthCheck healthCheck, bool isInStartupGracePeriod)
         {
             HealthCheck = healthCheck;
-            IsInStartupGraceperiod = isInStartupGraceperiod;
+            IsInStartupGracePeriod = isInStartupGracePeriod;
         }
     }
 }