Update app.js

@@ -84,7 +84,7 @@ async function handleEvent(event) {
     return new Promise(async(resolve,reject)=>{  
       fs.writeFileSync('./photo/image.png',event.message.image)
       var cheerio = require('cheerio');
-      
+      var file=fs.readFileSync('./photo/image.png');
       var uriBase = 'https://koreacentral.api.cognitive.microsoft.com/vision/v2.1/ocr';
        var options = {
         uri: uriBase,
@@ -97,7 +97,7 @@ async function handleEvent(event) {
           'Content-Type': 'application/octet-stream',
           'Ocp-Apim-Subscription-Key': '979dc5d63344438fa4701c62feebb7dc'
         },
-        body: fs.readFileSync('./photo/image.png')
+        body: file
       };
       
       request.post(options, function (error, response, body) {