Add back line removed in #2039 (#2043)

Author: timcosgrove

src/Robo/Commands/Vm/VmCommand.php

@@ -300,6 +300,7 @@ protected function customizeConfigFiles() {
     $config = clone $this->getConfig();
 
     $config->set('drupalvm.config.dir', $this->vmConfigDir);
+    $config->expandFileProperties($this->projectDrupalVmVagrantfile);
 
     // Generate a Random IP address for the new VM.
     $random_local_ip = "192.168." . rand(0, 255) . '.' . rand(0, 255);