OK status on failure getting HA mode

The check times out and then exits with OK and status 0.

```
[root@hlv]~# time ./check-paloalto-A500.pl -H 123.123.123.123 -C communitystring -t ha -w asd -c asd
OK: High Availablity Mode: , Local: , Peer: 


real    0m30.086s
user    0m0.047s
sys 0m0.007s
[root@hlv]~# echo $?
0
[root@hlv]~# 
```

Should probably exit with UNKNOWN or CRITICAL.
