Update v-add-fastcgi-cache

bin/v-add-fastcgi-cache

@@ -80,7 +80,7 @@ chmod 640 $fastcgi
 str="fastcgi_cache_path /var/cache/nginx/micro/$domain levels=1:2" 
 str="$str keys_zone=$domain:10m max_size=512m inactive=30m;" 
 conf='/etc/nginx/conf.d/fastcgi_cache_pool.conf'
-if [ -e "$conf" ]; then
+if [ -f "$conf" ]; then
     if [ -z "$(grep "=${domain}:" $conf)" ]; then
         echo "$str" >> $conf
     fi