title: error: Updating from such a repository can't be done securely, and is therefore disabled by default
body: <p>I've been trying to set up an intel realsense D415 on an Odroid XU4 and keep on running into the same error. As I am going through the commands at <a href="https://github.com/IntelRealSense/librealsense/blob/development/doc/distribution_linux.md" rel="nofollow noreferrer">https://github.com/IntelRealSense/librealsense/blob/development/doc/distribution_linux.md</a>, the below error pops up when I try to sudo apt-get update </p>
  
  <pre><code>odroid@odroid:~$ sudo apt-get update
  Get:1 http://deb.odroid.in/5422-s bionic InRelease [1701 B]
  Hit:2 http://ports.ubuntu.com/ubuntu-ports bionic InRelease                    
  Hit:3 http://ports.ubuntu.com/ubuntu-ports bionic-updates InRelease            
  Hit:4 http://archive.canonical.com/ubuntu bionic InRelease                     
  Hit:5 http://ppa.launchpad.net/apt-fast/stable/ubuntu bionic InRelease         
  Hit:6 http://ports.ubuntu.com/ubuntu-ports bionic-backports InRelease          
  Err:7 http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial InRelease
  403  Forbidden [IP: 52.218.80.49 80]
  Hit:8 http://ports.ubuntu.com/ubuntu-ports bionic-security InRelease    
  Err:9 http://realsense-alm-public.s3.amazonaws.com/apt-repo xenial InRelease
  403  Forbidden [IP: 52.218.80.49 80]
  Reading package lists... Done                      
  E: Failed to fetch http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo/dists/xenial/InRelease  403  Forbidden [IP: 52.218.80.49 80]
  E: The repository 'http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial InRelease' is not signed.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  E: Failed to fetch http://realsense-alm-public.s3.amazonaws.com/apt-repo/dists/xenial/InRelease  403  Forbidden [IP: 52.218.80.49 80]
  E: The repository 'http://realsense-alm-public.s3.amazonaws.com/apt-repo xenial InRelease' is not signed.
  N: Updating from such a repository can't be done securely, and is therefore disabled by default.
  N: See apt-secure(8) manpage for repository creation and user configuration details.
  </code></pre>
  
  <p>I've tried the --allow--unauthorized (don't remember exact syntax atm) even though I also read it only works with apt-get upgrade (not update). It did not work. Also tried with a brand new image. I've been able to run install on my ubuntu laptop with no problem. I've also been trying to add the repo manually but haven't been able to figure out how to.</p>