Update the curl utility in Debian 10

The default curl version, 7.64.0, in Debian 10 has known issues when attempting to reuse an already closed connection. This issue directly affects xbcloud and users may see intermittent backup failures.

For more details, see curl #3750 or curl #3763.

Follow these steps to upgrade curl to version 7.74.0:

1. Edit the /etc/apt/sources.list to add the following:

   deb http://ftp.de.debian.org/debian buster-backports main
   

2. Refresh the apt sources:

   $ sudo apt update
   

3. Install the version from buster-backports:

   $ sudo apt install curl/buster-backports
   

4. Verify the version number:

   $ curl --version
   

   Expected output

   curl 7.74.0 (x86_64-pc-linux-gnu) libcurl/7.74.0