~优化定时任务实现，尝试修复意外清空定时任务内容的bug

scripts/libs/set_cron.sh

@@ -3,15 +3,16 @@ crondir="$(crond -h 2>&1 | grep -oE 'Default:.*' | awk -F ":" '{print $2}')"
 [ ! -w "$crondir" ] && crondir="/etc/storage/cron/crontabs"
 [ ! -w "$crondir" ] && crondir="/var/spool/cron/crontabs"
 [ ! -w "$crondir" ] && crondir="/var/spool/cron"
-tmpcron="$TMPDIR"/cron_tmp
+tmpcron=/tmp/cron_tmp
+touch "$tmpcron"
 
 croncmd() { #定时任务工具
-	if [ -n "$(crontab -h 2>&1 | grep '\-l')" ]; then
-        crontab "$1"
-	elif [ -w "$crondir" ] && [ -n "$USER" ];then
+	if [ -w "$crondir" ] && [ -n "$USER" ];then
 		[ "$1" = "-l" ] && cat "$crondir"/"$USER" 2>/dev/null
 		[ -f "$1" ] && cat "$1" >"$crondir"/"$USER"
 		killall -HUP crond 2>/dev/null
+	elif [ -n "$(crontab -h 2>&1 | grep '\-l')" ]; then
+        crontab "$1"
 	else
 		echo "找不到可用的crond或者crontab应用！No available crond or crontab application can be found!"
 	fi
@@ -20,7 +21,6 @@ cronset() { #定时任务设置
     # 参数1代表要移除的关键字,参数2代表要添加的任务语句
     croncmd -l >"$tmpcron"
     sed -i "/$1/d" "$tmpcron"
-    sed -i '/^$/d' "$tmpcron"
     echo "$2" >>"$tmpcron"
     croncmd "$tmpcron"
     rm -f "$tmpcron"