[Minor] Fix multimap hostname check

diff --git a/src/plugins/lua/multimap.lua b/src/plugins/lua/multimap.lua
index 90d552a93f28a8c182492425e18e7b397068f924..723a469e5018a85e70924f186107bcea532283ee 100644 (file)
--- a/src/plugins/lua/multimap.lua
+++ b/src/plugins/lua/multimap.lua
@@ -536,7 +536,7 @@ local function multimap_callback(task, rule)
     match_content(rule)
   elseif rt == 'hostname' then
     local hostname = task:get_hostname()
-    if hostname ~= 'unknown' then
+    if hostname and hostname ~= 'unknown' then
       match_hostname(rule, hostname)
     end
   end