Hello, I'm not entirely sure what happens if you totally remove the key dns_resolution_time from the alarm profile. However, normally, just not having a value for that key, should stop any alarm.
If this is not happening, please try forcing a fresh restart of profile and probe.
1) deactivate the profile
2) deactivate the probe
3) aknowledge the alarm
4) Start the probe
5) open the profile, be sure there is no value in the dns resolution box
6) activate the profile