Update rguard to use install-lib (#689)

package/reboot-guard/package

@@ -5,7 +5,7 @@
 pkgnames=(reboot-guard)
 pkgdesc="Block systemd-initiated poweroff/reboot/halt until configurable condition checks pass"
 url=https://github.com/stephanritscher/reboot-guard
-pkgver=1.0.1-6
+pkgver=1.0.1-7
 timestamp=2020-05-04T06:16Z
 section="devel"
 maintainer="Eeems <eeems@eeems.email>"
@@ -34,8 +34,13 @@ configure() {
 }
 
 preremove() {
-    if systemctl list-units --full -all | grep -Fq 'rguard.service'; then
-        systemctl disable --now rguard
+    if is-active rguard.service; then
+        echo "Stopping rguard.service"
+        systemctl stop rguard.service
+    fi
+    if is-enabled rguard.service; then
+        echo "Disabling rguard.service"
+        systemctl disable rguard.service
     fi
 }