package/apparmor: fix permission bits for apparmor.service

Avoid setting executable bits for apparmor.service. This gets rid of a
corresponding warning during installation:
  Configuration file ../target/usr/lib/systemd/system/apparmor.service
  is marked executable. Please remove executable permission bits.
  Proceeding anyway.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/apparmor/apparmor.mk

@@ -88,7 +88,7 @@ endef
 define APPARMOR_INSTALL_INIT_SYSTEMD
 	$(INSTALL) -D -m 0755 $(@D)/parser/apparmor.systemd \
 		$(TARGET_DIR)/lib/apparmor/apparmor.systemd
-	$(INSTALL) -D -m 0755 $(@D)/parser/apparmor.service \
+	$(INSTALL) -D -m 0644 $(@D)/parser/apparmor.service \
 		$(TARGET_DIR)/usr/lib/systemd/system/apparmor.service
 endef