Fix night mode signal handling.

Now the script works on both FreeBSD and Linux, and it exits properly so switching between docked and undocked doesn't cause problems for waybar.

ansible/roles/waybar/files/waybar_scripts/waybar_night_mode.bash

@@ -21,7 +21,7 @@ function cleanup {
     kill "$wlsunset_pid"
     true
 }
-for sig in EXIT INT QUIT HUP TERM; do
+for sig in EXIT; do
   trap "set +e; cleanup" "$sig"
 done
 
@@ -85,7 +85,7 @@ function handle_click {
         log "Setting night mode to force-night."
         night_mode_mode="on"
     fi
-    kill -USR1 "$wlsunset_pid"
+    kill -s SIGUSR1 "$wlsunset_pid"
 }
 
 trap "handle_click" SIGUSR1