pfacct stores 00:00:00:00:00:00 MAC in DB when Calling-Station-ID is XXXX-XXXX-XXXX

[nqb]

Describe the bug
If pfacct receive an Accounting Request with a Calling-Station-ID that uses following convention: XXXX-XXXX-XXXX, an entry is created in bandwidth_accounting table with mac field equals to 00:00:00:00:00:00

To Reproduce
Steps to reproduce the behavior:

1. Forge an accounting request with specific Calling-Station-ID:

cat > /opt/acct << EOF
NAS-Port-Type = 15
Acct-Input-Octets = 0
Acct-Session-Id = 1111111 
NAS-IP-Address = 192.168.0.1
Called-Station-Id = "F4-E5-F2-FE-6B-61"
Calling-Station-Id = "ecf4-bb37-ddaa"
User-Name = "username@realm.com"
Acct-Authentic = 2
Acct-Status-Type = 3
Acct-Output-Packets = 0
Acct-Output-Octets = 0
Event-Timestamp = "Feb 07 2020 10:30:00 CET"
Acct-Input-Gigawords = 0
Acct-Input-Packets = 0
NAS-Port = 1
Acct-Delay-Time = 0
EOF

cat /opt/acct | radclient -x 172.17.17.10:1813 acct `cat /usr/local/pf/conf/local_secret`

2. mysql pf -e "select * from bandwidth_accounting;

=> Results:

+-----------------+----------------------+---------------------+-------------+----------+-----------+-------------------+-----------+---------------------+-------------+
| node_id         | unique_session_id    | time_bucket         | source_type | in_bytes | out_bytes | mac               | tenant_id | last_updated        | total_bytes |
+-----------------+----------------------+---------------------+-------------+----------+-----------+-------------------+-----------+---------------------+-------------+
| 281474976710656 | 14713129202345799727 | 2020-02-01 00:00:00 | radius      |        0 |         0 | 00:00:00:00:00:00 |         1 | 2021-01-27 13:19:30 |           0 |
+-----------------+----------------------+---------------------+-------------+----------+-----------+-------------------+-----------+---------------------+-------------+

Expected behavior
All format of MAC address should be supported.

Additional context
PacketFence is able to create an entry in cache because pfcmd cache accounting dump MAC returned accounting data.