Fixed some issues

frontend/src/components/RandomVideoUpload.tsx

@@ -71,6 +71,7 @@ const RandomSignUpload: React.FC = () => {
             // check if the sign is different from the current one
             if (sign === null || sign.id !== response.id) {
                 setSign(response);
+                setUploadProgress(null);
                 // set the video url
                 setSignVideo(response.video_url);
             } else {

frontend/src/services/signvideos.ts

@@ -10,8 +10,6 @@ const uploadSignVideo = async (id: number, recordedBlob: Blob, onUploadProgress:
     const response = await axios.post(`${process.env.REACT_APP_API_URL}/signs/${id}/video/`, formData, {
         headers: {
             ContentType: 'multipart/form-data',
-            // close the connection after the request is sent
-            Connection: 'close',
         },
         onUploadProgress: (progressEvent) => {
             onUploadProgress(