Bugfix: crash deleting when activity restarts. Fixes #705.

src/main/java/de/dennisguse/opentracks/TrackDeleteActivity.java

@@ -64,26 +64,29 @@ public class TrackDeleteActivity extends AbstractActivity {
 
             runOnUiThread(TrackDeleteActivity.this::onAsyncTaskCompleted);
         });
-    }
-
-    @Override
-    protected void onStart() {
-        super.onStart();
         deleteThread.start();
     }
 
-    @Override
-    protected void onStop() {
-        super.onStop();
-        deleteThread.interrupt();
-    }
-
     @Override
     protected void onDestroy() {
         super.onDestroy();
         viewBinding = null;
     }
 
+    @Override
+    protected void onStart() {
+        super.onStart();
+        if (deleteThread.getState() == Thread.State.TERMINATED) {
+            onAsyncTaskCompleted();
+        }
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        deleteThread.interrupt();
+    }
+
     @Override
     protected View getRootView() {
         viewBinding = TrackDeleteBinding.inflate(getLayoutInflater());