Revert "CLOUDSTACK-7821: Fix OSX cannot connect to VPN due to wrongly declaim ENCAPSULATION_MODE_UDP_TRANSPORT_RFC"

This reverts commit e1c788ca3c69a8c8c2041c7b106f76fa49332888.

It breaks Windows 7 client.
CLOUDSTACK-7918:
guest os name changes from 'SUSE Linux Enterprise Server 12 (experimental)' to 'SUSE Linux Enterprise Server 12 (64-bit)' in latest XS 5.6 ,
changed the guest OS mapping to fix it.