Rename mailserver.loginAccounts to mailserver.accounts

The "login" prefix makes this option more confusing rather than clearer,
because what other account types are there? LDAP ones for example, but
you can login with those too, so the prefix is pointless.

docs/radicale.nix

@@ -12,7 +12,7 @@ let
     mapAttrsToList
     ;
 
-  mailAccounts = config.mailserver.loginAccounts;
+  mailAccounts = config.mailserver.accounts;
   htpasswd = pkgs.writeText "radicale.users" (
     concatStrings (flip mapAttrsToList mailAccounts (mail: user: "${mail}+:${user.hashedPassword}\n"))
   );