bugfix. installing desktop when switching beta/stable

debian-config-functions

@@ -327,7 +327,7 @@ function reload_bsp(){
 		# if new packages are absent, reinstall old ones
 		if [[ -z $PACKAGE_LIST ]]; then
 			PACKAGE_LIST="linux-${DISTROID}-root$TARGET_BRANCH-$BOARD"
-			[[ -n $(apt-cache search --names-only "^armbian-${DISTROID}-desktop$") ]] && PACKAGE_LIST=$PACKAGE_LIST" armbian-${DISTROID}-desktop"
+			check_if_installed armbian-${DISTROID}-desktop && PACKAGE_LIST=$PACKAGE_LIST" armbian-${DISTROID}-desktop"
 		fi
 
 		# reinstall headers only if they are already installed