TMP Merge commit EDNS0 buffer reduction into 0x20-only-udp

diff --cc NEWS
index 5962f1d3be7f9c06935338859cf516f0cb973951,30ae5aff67effd2f522557cebac296869dcea61a..b5dc884e23e4ff722384bee4b8b9c05bad90a9ac
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -1,12 -1,9 +1,13 @@@
  Knot Resolver 5.2.0 (2020-1m-dd)
  ================================
  
 +Incompatible changes
 +--------------------
 +- build: meson >= 0.49 is required (!1082)
 +
  Improvements
  ------------
+ - lower default EDNS buffer size to 1232 (#538, #300, !920)
  - net: split the EDNS buffer size into upstream and downstream (!1026)
  - lua-http doh: answer to /dns-query endpoint as well as /doh (!1069)
  - improve resiliency against UDP fragmentation attacks (disable PMTUD) (!1061)