I don't suggest you doing that because you are changing the permissions of the data folder and it could be possible that the application doesn't have the correct permissions to use that folder.
Please, change the permissions again with the following command:
chown -R daemon /opt/bitnami/apps/owncloud/data
If you want to watch the files inside the data folder, you can get super user privileges using the following command:
Be careful because you will create files and folder using the root user.
If you want to exit you have to run the following command:
Let us know if it works for you!