Issue #3296108 by catch, dww, Spokje, mondrake: mysql_requirements() assumes...

Issue #3296108 by catch, dww, Spokje, mondrake: mysql_requirements() assumes it's used for the default connection

core/modules/mysql/mysql.install

@@ -17,6 +17,10 @@ function mysql_requirements($phase) {
     // Test with MySql databases.
     if (Database::isActiveConnection()) {
       $connection = Database::getConnection();
+      // Only show requirements when MySQL is the default database connection.
+      if (!($connection->driver() === 'mysql' && $connection->getProvider() === 'mysql')) {
+        return [];
+      }
 
       $query = 'SELECT @@SESSION.tx_isolation';
       // The database variable "tx_isolation" has been removed in MySQL v8.0 and