Tweaked SingleInstancePolicy not to cancel startup if AppData is overridden is set.

src/NzbDrone.Host/Bootstrap.cs

@@ -88,11 +88,15 @@ namespace NzbDrone.Host
         {
             var instancePolicy = _container.Resolve<ISingleInstancePolicy>();
 
-            if (isService)
+            if (startupContext.Flags.Contains(StartupContext.TERMINATE))
             {
                 instancePolicy.KillAllOtherInstance();
             }
-            else if (startupContext.Flags.Contains(StartupContext.TERMINATE))
+            else if (startupContext.Args.ContainsKey(StartupContext.APPDATA))
+            {
+                instancePolicy.WarnIfAlreadyRunning();
+            }
+            else if (isService)
             {
                 instancePolicy.KillAllOtherInstance();
             }

src/NzbDrone.Host/SingleInstancePolicy.cs

@@ -10,6 +10,7 @@ namespace NzbDrone.Host
     {
         void PreventStartIfAlreadyRunning();
         void KillAllOtherInstance();
+        void WarnIfAlreadyRunning();
     }
 
     public class SingleInstancePolicy : ISingleInstancePolicy
@@ -45,6 +46,14 @@ namespace NzbDrone.Host
             }
         }
 
+        public void WarnIfAlreadyRunning()
+        {
+            if (IsAlreadyRunning())
+            {
+                _logger.Debug("Another instance of Sonarr is already running.");
+            }
+        }
+
         private bool IsAlreadyRunning()
         {
             return GetOtherNzbDroneProcessIds().Any();