firewall: bump to version 2020-07-05
Changes since last source version
e9b90df zones: apply tcp mss clamping also on ingress path
050816a redirects: fix segmentation fault
f62a52b treewide: replace unsafe string functions
23cc543 improve reload logic
9d7f49d redurects: add support to define multiple zones for dnat reflection rules
f87d0b0 firewall3: defaults: fix uci flow_offloading option
fe9602c rules: fix typo
7cc2a84 defaults: robustify flow table detection.
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>