QSY with rigtcld changes filter bandwitdh

[cwhelchel]

Describe the bug
When QSY-ing with HL using rigctld CAT control, the bandwidth of the filter will change unexpectedly. This is because the command to change mode M CW 0 passes in 0 which tells hamlib to use it's good default for that mode.

Expected behavior
It should use the last user set filter bandwidth.

Desktop (please complete the following information):

• OS: Win
• Hunterlog application version: 0.0.10-devC
• Hunterlog database version: N/A

Additional context
Change command to M CW -1. While not documented well, the rigctld source shows that it will use that flag to ignore setting the filter bandwidth for the mode.