Merge pull request #15677 from miodvallat/enlarge_your_map

LMDB: honour map-size for all files

diff --cc ext/lmdb-safe/lmdb-safe.hh
Simple merge

diff --cc modules/lmdbbackend/lmdbbackend.cc
Simple merge

diff --cc modules/lmdbbackend/lmdbbackend.hh
Simple merge