rigctld: sending cw seems broken
I'm not sure when an issue is started.
few days ago, I found an issue when I try to send cw message via QLog(hamlib + rigctld)
here is wfview log
```
2026-05-20 13:00:55.588 DBG rigctld: 6052 RX: "\\send_morse TEST MORSE MESSAGE "
2026-05-20 13:00:55.603 DBG rig: CW input: "end_morse TEST MORSE MESSAGE "
2026-05-20 13:00:55.603 WRN rig: Invalid character detected in CW message at position 3 , the character is '_'
2026-05-20 13:00:55.603 DBG rig: CW output:: "end?morse TEST MORSE MESSAGE "
2026-05-20 13:00:55.603 DBG rig: Sending CW: payload: "17 65 6e 64 3f 6d 6f 72 73 65 20 54 45 53 54 20 4d 4f 52 53 45 20 4d 45 53 53 41 47 45 20"
```
cutting command section seems broken.
tested with
- wfview: 2.21
- ICOM IC-7300
issue