Crash on startup saying "Unsupported extension used"

[tpwrules]

Ran into this error upgrading my system to lxqt-powermanagement 1.4.0.

$ lxqt-powermanagement
BatteryChanged discharging: false chargeLevel: 100 actionTime: QTime(Invalid)
Inhibit got: 34
Starting idlenesswatcher
The X11 connection broke: Unsupported extension used (code 2)
XIO:  fatal IO error 2 (No such file or directory) on X server ":0"
      after 311 requests (311 known processed) with 0 events remaining. 

This ended up being due to the following text in my X11 config file:

    Section "Extensions"
      Option      "DPMS" "Disable"
    EndSection
    Section "ServerFlags"
      Option "BlankTime" "0"
    EndSection

This was originally added to address the issue now solved by #374 . However, this method of disabling DPMS causes the invocation to attempt to set its timeout to crash.

This issue has two purposes:

1. In case anybody has this same problem, they can find the fix.
2. To ask if there's a way to check for the extension before attempting to set the timeout to avoid a crash. Not sure if there are circumstances where DPMS can be disabled without the user doing it deliberately.