Drop clear download path cache

Useless and will cause redownload

app/src/main/java/com/hippo/ehviewer/preference/ClearDownloadPathCachePreference.java

@@ -1,65 +0,0 @@
-/*
- * Copyright 2016 Hippo Seven
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.hippo.ehviewer.preference;
-
-import android.content.Context;
-import android.util.AttributeSet;
-
-import androidx.appcompat.app.AlertDialog;
-
-import com.hippo.ehviewer.EhDB;
-import com.hippo.ehviewer.R;
-import com.hippo.preference.MessagePreference;
-
-public class ClearDownloadPathCachePreference extends MessagePreference {
-
-    public ClearDownloadPathCachePreference(Context context) {
-        super(context);
-        init(context);
-    }
-
-    public ClearDownloadPathCachePreference(Context context, AttributeSet attrs) {
-        super(context, attrs);
-        init(context);
-    }
-
-    public ClearDownloadPathCachePreference(Context context,
-                                            AttributeSet attrs, int defStyleAttr) {
-        super(context, attrs, defStyleAttr);
-        init(context);
-    }
-
-    public void init(Context context) {
-        setDialogMessage(context.getString(R.string.settings_advanced_clear_download_path_cache_message));
-    }
-
-    @Override
-    protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
-        super.onPrepareDialogBuilder(builder);
-        builder.setTitle(null);
-        builder.setNegativeButton(android.R.string.cancel, null);
-    }
-
-    @Override
-    protected void onDialogClosed(boolean positiveResult) {
-        super.onDialogClosed(positiveResult);
-
-        if (positiveResult) {
-            EhDB.clearDownloadDirname();
-        }
-    }
-}