fix mapping multiple tuner channels to same epg channel

Emby.Common.Implementations/BaseApplicationHost.cs

@@ -873,7 +873,13 @@ return null;
         /// Gets or sets a value indicating whether this instance can self update.
         /// </summary>
         /// <value><c>true</c> if this instance can self update; otherwise, <c>false</c>.</value>
-        public abstract bool CanSelfUpdate { get; }
+        public virtual bool CanSelfUpdate
+        {
+            get
+            {
+                return false;
+            }
+        }
 
         /// <summary>
         /// Checks for update.

Emby.Common.Implementations/ScheduledTasks/ScheduledTaskWorker.cs

@@ -379,7 +379,7 @@ namespace Emby.Common.Implementations.ScheduledTasks
         /// <exception cref="System.InvalidOperationException">Cannot execute a Task that is already running</exception>
         public async Task Execute(TaskExecutionOptions options)
         {
-            var task = ExecuteInternal(options);
+            var task = Task.Run(async () => await ExecuteInternal(options).ConfigureAwait(false));
 
             _currentTask = task;