remove code

src/jensen.js

@@ -759,7 +759,6 @@ Jensen.prototype.getFile = async function (filename, length, ondata, onprogress)
             flen += msg.body.length || msg.body.byteLength;
             ondata(msg.body);
             Logger.info('jensen', 'getFile length', `${length} ${flen}`)
-            clearEventAndTask();
             if (flen >= length) {
                 document.removeEventListener('visibilitychange', visibilitychange);
                 Logger.info('jensen', 'getFile', 'file download finish.')