[PATCH] replaced deprecated apt-key usage

apt-key was deprecated some Debian versions ago. This change follows the
first suggestion for the DEPRECATION section of apt-key manpages.
---
templates/pages/download/linux/debian.html | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/templates/pages/download/linux/debian.html
b/templates/pages/download/linux/debian.html
index 2cfbd240..e2c36d25 100644
--- a/templates/pages/download/linux/debian.html
+++ b/templates/pages/download/linux/debian.html
@@ -49,7 +49,8 @@ <h2>PostgreSQL Apt Repository</h2>
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt
$(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'

# Import the repository signing key:
-wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc |
sudo apt-key add -
+wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc |
sudo tee /etc/apt/trusted.gpg.d/apt.postgresql.org.asc
+

# Update the package lists:
sudo apt-get update