Remove old cache dir preference

nitter.conf

@@ -7,7 +7,6 @@ title = "nitter"
 hostname = "nitter.net"
 
 [Cache]
-directory = "./tmp"
 listMinutes = 240  # how long to cache list info (not the tweets, so keep it high)
 rssMinutes = 10  # how long to cache rss queries
 redisHost = "localhost"