nixos/mediawiki: wfGetDB removed

MediaWiki 1.44 has removed the wfGetDB function, so the init script
can no longer use it

Release notes: https://www.mediawiki.org/wiki/Release_notes/1.44#Breaking_changes_in_1.44

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

@@ -713,7 +713,7 @@ in
           tr -dc A-Za-z0-9 </dev/urandom 2>/dev/null | head -c 64 > ${stateDir}/secret.key
         fi
 
-        echo "exit( wfGetDB( DB_PRIMARY )->tableExists( 'user' ) ? 1 : 0 );" | \
+        echo "exit( \$this->getPrimaryDB()->tableExists( 'user' ) ? 1 : 0 );" | \
         ${php}/bin/php ${pkg}/share/mediawiki/maintenance/eval.php --conf ${mediawikiConfig} && \
         ${php}/bin/php ${pkg}/share/mediawiki/maintenance/install.php \
           --confpath /tmp \