Remove unused observer

app/src/main/java/chat/rocket/android/service/observer/TokenLoginObserver.java

-package chat.rocket.android.service.observer;
-
-import android.content.Context;
-
-import java.util.List;
-
-import chat.rocket.android.api.MethodCallHelper;
-import chat.rocket.android.helper.LogIfError;
-import chat.rocket.persistence.realm.RealmHelper;
-import chat.rocket.persistence.realm.models.internal.RealmSession;
-import io.realm.Realm;
-import io.realm.RealmResults;
-
-public class TokenLoginObserver extends AbstractModelObserver<RealmSession> {
-
-  private final MethodCallHelper methodCall;
-
-  public TokenLoginObserver(Context context, String hostname,
-                            RealmHelper realmHelper) {
-    super(context, hostname, realmHelper);
-    methodCall = new MethodCallHelper(realmHelper);
-  }
-
-  @Override
-  public RealmResults<RealmSession> queryItems(Realm realm) {
-    return realm.where(RealmSession.class)
-        .isNotNull(RealmSession.TOKEN)
-        .equalTo(RealmSession.TOKEN_VERIFIED, false)
-        .isNull(RealmSession.ERROR)
-        .findAll();
-  }
-
-  @Override
-  public void onUpdateResults(List<RealmSession> results) {
-    if (results.isEmpty()) {
-      return;
-    }
-
-    RealmSession session = results.get(0);
-    methodCall.loginWithToken(session.getToken()).continueWith(new LogIfError());
-  }
-}