config: Mitigate upcoming SSL CVE

See
https://mta.openssl.org/pipermail/openssl-announce/2022-October/000238.html

As 1.1 is unaffected, this override should be sufficient to evade this
problem.

configuration/default.nix

@@ -25,6 +25,10 @@
         pkgs = prev;
         lib = prev.lib;
       };
+
+      # Mitigate
+      # https://mta.openssl.org/pipermail/openssl-announce/2022-October/000238.html
+      nginxStable = prev.nginxStable.override {openssl = prev.openssl_1_1;};
     })
   ];