Fields missing when APRS packet is a message

Hi! Encountered a potential bug.

Running v5.0.

A friend sent a message over APRS earlier on today. On the GUI the only fields that are populated are From and To.

```+ Packet ---+-----------+----------+----------+-----------------------------+-----------------------------+
| From | To | Lat | Long | Comment | Text |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+
| MM6ONE-9 | APY100 | | | | |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+

+ Packet ---+-----------+----------+----------+-----------------------------+-----------------------------+
| From | To | Lat | Long | Comment | Text |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+
| MM6ONE-9 | APY100 | | | | |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+
```
When checking the application logs, the message can be viewed from there.
```
[2020-06-01 12:52:25,520] [INFO] MM6ONE-9>APY100,WIDE1-1,WIDE2-1::MM6TWO-10:hi u up for qso 2morro 1215 on 433.525?{05
[2020-06-01 12:53:01,829] [INFO] MM6ONE-9>APY100,WIDE1-1,WIDE2-1::MM6TWO-10:hi u up for qso 2morro 1215 on 433.525?{05
```
I'm able to replicate the issue sending a message directed to the call sign also.

```
+ Packet ---+-----------+----------+----------+-----------------------------+-----------------------------+
| From | To | Lat | Long | Comment | Text |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+
| MM6TWO-7 | APK003 | | | | |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+

+ Packet ---+-----------+----------+----------+-----------------------------+-----------------------------+
| From | To | Lat | Long | Comment | Text |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+
| MM6TWO-7 | APK003 | | | | |
+-----------+-----------+----------+----------+-----------------------------+-----------------------------+
```

```
[2020-06-01 14:11:47,030] [INFO] MM6TWO-7>APK003,WIDE1-1,WIDE2-2::MM6ONE-9 :rgr_that!{0
[2020-06-01 14:12:47,513] [INFO] MM6TWO-7>APK003,WIDE1-1,WIDE2-2::MM6ONE-9 :rgr_that!{0
```
It looks like "From" is being picked up from the packet correctly, but the [to-call](http://aprs.org/aprs11/tocalls.txt) version is set as "To" and the rest is missing from the readable output.

If you need anything else, let me know!

Edit: I realise that messages may not fit within the design/purpose of the application.