Cleanup unused code and messages

Author: CrAazZyMaN21

roles/netbootxyz/templates/menu/rhcos.ipxe.j2

@@ -18,12 +18,10 @@ item --gap ${os}:
 {% for item in releases.rhcos.versions %}
 item {{ item.code_name }} ${space} ${os} {{ item.name }}
 {% endfor %}
-item url_set ${space} Set Base URL: ${rhcos_base_url}
 item install_dev ${space} Set install device: ${install_device}
 item ignition_config ${space} Set ignition config url: ${ignition_url}
 choose --default ${rhcos_version} rhcos_version || goto rhcos_exit
 echo ${cls}
-iseq ${rhcos_version} url_set && goto url_set ||
 iseq ${rhcos_version} ignition_config && goto ignition_config ||
 iseq ${rhcos_version} install_dev && goto install_dev ||
 goto rhcos_boot ||
@@ -42,6 +40,8 @@ boot
 goto rhcos_exit
 
 :install_dev
+echo -n Selected install device will be overwritten,
+echo -n please ensure you know what are you doing...
 echo -n Please set desired install device:  && read install_device
 clear menu
 goto rhcos