Merge !295: validate: avoid keeping KR_RANK_MISSING

diff --cc NEWS
index 86fe35980d1995d4a6b319d58610b3b4e9f894f8,75c0ca512e2cf0478646c01684d88bbfe833e0de..33827c7c2939d3f049fd1b0a3a8ab4f51ae91bc6
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -13,11 -13,10 +13,14 @@@ Improvement
  - allow answering from cache in non-iterative modes (#122)
  - command line: specify ports via @ but still support # for compatibility
  - policy: recognize 100.64.0.0/10 as local addresses
 +- layer/iterate: *do* retry repeatedly if REFUSED, as we can't yet easily
 +  retry with other NSs while avoiding retrying with those who REFUSED
 +- modules: allow changing the directory where modules are found,
 +  and do not search the default library path anymore.
  
+ Bugfixes
+ --------
+ - validate: fix insufficient caching for some cases (relatively rare)
  
  Knot Resolver 1.2.6 (2017-04-24)
  ================================

diff --cc lib/layer/validate.c
Simple merge