Enable Debug for dev only

Because doctrine/static-website-generator has a dependency to symfony/http-kernel
that installs symfony/error-handler as a no-dev dependency, the Debug class
is always available and enables Debug mode even in prod.

bin/console

@@ -10,7 +10,7 @@ use Symfony\Component\ErrorHandler\Debug;
 $input = new ArgvInput();
 $env = $input->getParameterOption(['--env', '-e'], 'dev');
 
-if (class_exists(Debug::class)) {
+if (class_exists(Debug::class) && $env === 'dev') {
     Debug::enable();
 }