Update install.md
Fixes installation error:
N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'https://releases.algorand.com/deb stable InRelease' doesn't support architecture 'i386'
when installing on a 64-bit machine that has i386 support on Ubuntu 20.04 LTS (which can be found by):
dpkg --print-foreign-architectures
> i386
dpkg --print-architecture
> amd64
@@ -90,7 +90,7 @@ sudo apt-get update
sudo apt-get install -y gnupg2 curl software-properties-common
curl -O https://releases.algorand.com/key.pub
sudo apt-key add key.pub
-sudo add-apt-repository "deb https://releases.algorand.com/deb/ stable main"
+sudo add-apt-repository "deb [arch=amd64] https://releases.algorand.com/deb/ stable main"
sudo apt-get update
# To get both algorand and the devtools:
