outdated version is now NC26

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

app/src/main/java/com/owncloud/android/MainApp.java

@@ -124,7 +124,7 @@ import static com.owncloud.android.ui.activity.ContactsPreferenceActivity.PREFER
  * Contains methods to build the "static" strings. These strings were before constants in different classes.
  */
 public class MainApp extends MultiDexApplication implements HasAndroidInjector {
-    public static final OwnCloudVersion OUTDATED_SERVER_VERSION = NextcloudVersion.nextcloud_23;
+    public static final OwnCloudVersion OUTDATED_SERVER_VERSION = NextcloudVersion.nextcloud_26;
     public static final OwnCloudVersion MINIMUM_SUPPORTED_SERVER_VERSION = OwnCloudVersion.nextcloud_16;
 
     private static final String TAG = MainApp.class.getSimpleName();