Merge pull request #1570 from SkynetLabs/fix-empty-blocklist-error

check if blocklist is not null

docker/nginx/libs/skynet/blocklist.lua

@@ -26,10 +26,13 @@ function _M.reload()
         -- mark all existing entries as expired
         ngx.shared.blocklist:flush_all()
 
+        -- check if blocklist is table (it is null when empty)
+        if type(data.blocklist) == "table" then
             -- set all cache entries one by one (resets expiration)
             for i, hash in ipairs(data.blocklist) do
                 ngx.shared.blocklist:set(hash, true)
             end
+        end
 
         -- ensure that init flag is persisted
         ngx.shared.blocklist:set("__init", true)