only use camera for pictures and use default mime jpeg

src/uppy/UppyHelperClass.js

@@ -43,7 +43,9 @@ export default class UppyHelperClass {
       proudlyDisplayPoweredByUppy: false,
       showLinkToFileUploadResult: false
     }).use(Uppy.Webcam, {
-      target: Uppy.Dashboard
+      target: Uppy.Dashboard,
+      modes: ['picture'],
+      preferredImageMimeType: 'image/jpeg'
     }).use(JSONUploader, {
       endpoint: uploadEndpoint
     })