[mod_maxminddb] fix config validation typo

(bug on master branch; never released)

(thx maxentry)

x-ref:
  "maxminddb.env error 1.4.56"
  https://redmine.lighttpd.net/boards/2/topics/9480

src/mod_maxminddb.c

@@ -285,7 +285,7 @@ SETDEFAULTS_FUNC(mod_maxminddb_set_defaults)
         T_CONFIG_STRING,
         T_CONFIG_SCOPE_CONNECTION }
      ,{ CONST_STR_LEN("maxminddb.env"),
-        T_CONFIG_ARRAY_VLIST,
+        T_CONFIG_ARRAY_KVSTRING,
         T_CONFIG_SCOPE_CONNECTION }
      ,{ NULL, 0,
         T_CONFIG_UNSET,