Only send low peripheral battery notification when in discharging state

Otherwise this notification is sent when connecting devices
with "unknown" battery state (State = 0 in upower).

Differential Revision: https://phabricator.kde.org/D9575

daemon/powerdevilcore.cpp

@@ -514,7 +514,7 @@ bool Core::emitBatteryChargePercentNotification(int currentPercent, int previous
     if (b && !b->isPowerSupply()) {
         // if you leave the device out of reach or it has not been initialized yet
         // it won't be "there" and report 0%, don't show anything in this case
-        if (!b->isPresent()) {
+        if (!b->isPresent() || b->chargeState() != Battery::Discharging) {
             return false;
         }