os-ddclient: Config file is not written correctly by WebGUI

[DontDieKid0013]

Important notices Before you add a new report, we ask you kindly to acknowledge the following:

• [ x ] I have read the contributing guide lines at https://github.com/opnsense/plugins/blob/master/CONTRIBUTING.md
• [ x ] I have searched the existing issues, open and closed, and I'm convinced that mine is new.
• [ x ] The title contains the plugin to which this issue belongs

Describe the bug When using the OpnSense WebGUI to update an entry for ddclient, upon further inspection the config file is written incorrectly causing ddclient to not be able to parse, reverting to default settings.

To Reproduce Steps to reproduce the behavior:

1. Install os-ddclient via the WebGUI version 1.27_1
2. Configure a hostname to update with service: no-ip, username, password, and hostname: all correct, check ip method: ipify-ipv4, interface: lan
3. Note that logs in the WebGUI say: WARNING: '' is not a valid IPv4 or IPv6 address, WARNING: found neither IPv4 nor IPv6 address
4. Note that running ddclient from the shell with this command: sudo ddclient -file /usr/local/etc/ddclient.conf -daemon=0 -debug -verbose -noquiet has a line that notes: WARNING: yourdomain.ddns.net: unable to determine IP address with strategy use=ip
5. View the config file at /usr/local/etc/ddclient.conf with a shell text editor to see that the following lines are followed by a comma and backslash, breaking parsing: use=cmd, cmd="/usr/local/opnsense/scripts/ddclient/checkip -i em0 -t 1 -s ipify-ipv4 --timeout 10", \ protocol=noip, \ login=login, \ password=pass \

Expected behavior There should be no spaces, commas, or backslashes following the end of each line

Environment opnsense 25.1.5_5