config-tools: fix guest_flag issue in config xml for adl
commit ("misc: sanity check VM config for nested virtualization")
requires that the guest_flag tag can't be empty, or it will fail to build.
This patch changes adl instances of "<guest_flag></guest_flag>" to
"<guest_flag>0</guest_flag>".
<vm_type>SOS_VM</vm_type>
<name>ACRN SOS VM</name>
<guest_flags>
- <guest_flag/>
+ <guest_flag>0</guest_flag>
</guest_flags>
<clos>
<vcpu_clos>0</vcpu_clos>
<vm id="1">
<vm_type>POST_STD_VM</vm_type>
<guest_flags>
- <guest_flag/>
+ <guest_flag>0</guest_flag>
</guest_flags>
<cpu_affinity>
<pcpu_id>0</pcpu_id>
