Use AndroidX

app/src/main/java/com/hippo/ehviewer/Hosts.java

@@ -25,8 +25,8 @@ import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
-import android.support.annotation.Nullable;
 import android.util.Pair;
+import androidx.annotation.Nullable;
 import com.hippo.database.MSQLiteBuilder;
 import com.hippo.util.SqlUtils;
 import java.net.InetAddress;