Get a better fix that doesn't break the current assumptions of how finally handlers are called

Author: shana

src/GitHub.Api/Application/ApplicationManagerBase.cs

@@ -107,14 +107,14 @@ public void Run(bool firstRun)
                 Logger.Trace("Using portable git");
 
                 var setupGit = new GitInstaller(Environment, ProcessManager, TaskManager).SetupGitIfNeeded();
+                t.Then(setupGit);
                 setupGit.Finally((s, state) =>
                 {
                     endTask.PreviousResult = state;
                     endTask.Start();
                 });
                 setupGit.Progress(progressReporter.UpdateProgress);
                 // append installer task to top chain
-                t.Then(setupGit);
             };
 
             var setupChain = setExistingEnvironmentPath.Then(setupOctorun);

src/GitHub.Api/Tasks/TaskBase.cs

@@ -671,8 +671,7 @@ protected virtual void RaiseOnEnd(TResult data)
         protected override void CallFinallyHandler()
         {
             finallyHandler?.Invoke(!taskFailed, result);
-            if (finallyHandler == null)
-                base.CallFinallyHandler();
+            base.CallFinallyHandler();
         }
 
         public new Task<TResult> Task