Initialise known_ips with character(0)

geoip.R

@@ -12,6 +12,8 @@ dbConnect(SQLite(), "access.db") %>%
 dbConnect(SQLite(), "access.db") %>%
   dbGetQuery("vacuum;")
 
+known_ips <- character(0)
+
 src_sqlite("access.db") %>%
   tbl("geoip") %>%
   select(query) %>%