To reproduce:
set vpn openconnect authentication mode local commit
Traceback (most recent call last):
File "/usr/libexec/vyos/conf_mode/vpn_openconnect.py", line 147, in <module>
verify(c)
File "/usr/libexec/vyos/conf_mode/vpn_openconnect.py", line 64, in verify
if not ocserv["authentication"]["local_users"] or not ocserv["authentication"]["local_users"]["username"]:
KeyError: 'local_users'