Switched splash screen start

The splash screen was added to prevent seeing the "non-ready" MainActivity.
If the splash is closed before showing MainActivity, the splash does
nothing in most cases, just flashes the screen blue for a few milliseconds.
After that, you see MainActivity just as it was before adding the splash.

app/src/main/java/de/danoeh/antennapod/activity/SplashActivity.java

@@ -44,8 +44,8 @@ public class SplashActivity extends AppCompatActivity {
             .observeOn(AndroidSchedulers.mainThread())
             .subscribe(() -> {
                 Intent intent = new Intent(SplashActivity.this, MainActivity.class);
-                finish();
                 startActivity(intent);
+                finish();
             });
     }
 }