nixos/matomo: better check for database being set up

Since matomo-5.2.0, the config.php.ini is already created when first
accessing the installer page without completing it. This breaks our
discovery of whether to run database migrations.

Attempting to run DB migrations without provided database credentials
causes a crash -> causing matomo-setup-update.service to fail -> causing
phpfpm-matomo.service to fail.

Author: osnyx

nixos/modules/services/web-apps/matomo.nix

@@ -183,7 +183,10 @@ in {
             chmod -R u+rwX,g+rwX,o-rwx "${dataDir}"
 
             # check whether user setup has already been done
-            if test -f "${dataDir}/config/config.ini.php"; then
+            if test -f "${dataDir}/config/config.ini.php" &&
+              # since matomo-5.2.0, the config.ini.php is already created at first
+              # installer page access https://github.com/matomo-org/matomo/issues/22932
+              grep -q -F "[database]" "${dataDir}/config/config.ini.php"; then
               # then execute possibly pending database upgrade
               matomo-console core:update --yes
             fi