nixos/mautrix-telegram: update defaults

These three defaults must exist in the config now, otherwise
`mautrix-telegram` will refuse to start.

nixos/modules/services/misc/mautrix-telegram.nix

@@ -21,6 +21,7 @@ in {
         default = {
           appservice = rec {
             database = "sqlite:///${dataDir}/mautrix-telegram.db";
+            database_opts = {};
             hostname = "0.0.0.0";
             port = 8080;
             address = "http://localhost:${toString port}";
@@ -29,6 +30,8 @@ in {
           bridge = {
             permissions."*" = "relaybot";
             relaybot.whitelist = [ ];
+            double_puppet_server_map = {};
+            login_shared_secret_map = {};
           };
 
           logging = {