Fixes populate command error

Author: merk

Command/PopulateCommand.php

@@ -74,7 +74,7 @@ protected function initialize(InputInterface $input, OutputInterface $output)
         $this->resetter = $this->getContainer()->get('fos_elastica.resetter');
         $this->progressClosureBuilder = new ProgressClosureBuilder();
 
-        if (!$input->getOption('no-overwrite-format')) {
+        if (!$input->getOption('no-overwrite-format') && class_exists('Symfony\\Component\\Console\\Helper\\ProgressBar')) {
             ProgressBar::setFormatDefinition('normal', " %current%/%max% [%bar%] %percent:3s%%\n%message%");
             ProgressBar::setFormatDefinition('verbose', " %current%/%max% [%bar%] %percent:3s%% %elapsed:6s%\n%message%");
             ProgressBar::setFormatDefinition('very_verbose', " %current%/%max% [%bar%] %percent:3s%% %elapsed:6s%/%estimated:-6s%\n%message%");