further update GPGMiniHowto.html links

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

backend/tests/test_email.py

@@ -157,7 +157,7 @@ then visit to make your entry confirmed.
 
 You should not need instructions to decrypt this. If you do not know how to do
 it, you can consider it a challenge. In that case, you can start from here:
-https://www.dewinter.com/gnupg_howto/english/GPGMiniHowto.html
+https://www.gnupg.org/howtos/en/GPGMiniHowto.html
 
 For any problem, feel free to contact Front Desk at nm@debian.org.
 

public/templates/public/newnm.html

@@ -366,7 +366,7 @@ Policies (DMUP) when you use Debian resources?{% endblocktrans %}
 
     <p>{% blocktrans %}Most Debian work is not anonymous, and requires the
 use of an <a
-    href="https://www.dewinter.com/gnupg_howto/english/GPGMiniHowto.html">OpenPGP</a>
+    href="https://www.gnupg.org/howtos/en/GPGMiniHowto.html">OpenPGP</a>
 key. We require the key to be signed or endorsed by two (one for people applying to become
 Debian Maintainer) or more Debian Developers to make reasonably sure that you
 are who you claim to be. This is called the

public/tests/test_newnm.py

@@ -151,7 +151,7 @@ then visit to make your entry confirmed.
 
 You should not need instructions to decrypt this. If you do not know how to do
 it, you can consider it a challenge. In that case, you can start from here:
-https://www.dewinter.com/gnupg_howto/english/GPGMiniHowto.html
+https://www.gnupg.org/howtos/en/GPGMiniHowto.html
 
 For any problem, feel free to contact Front Desk at nm@debian.org.