Remove unused code

server/database.js

@@ -30,11 +30,6 @@ class Database {
      */
     static patched = false;
 
-    /**
-     * For Backup only
-     */
-    static backupPath = null;
-
     /**
      * Add patch filename in key
      * Values:
@@ -357,8 +352,6 @@ class Database {
                 }
             }
 
-            this.backup(dayjs().format("YYYYMMDDHHmmss"));
-
             log.info("db", sqlFilename + " is patching");
             this.patched = true;
             await this.importSQLFile("./db/" + sqlFilename);