Log Message:
libmaxminddb: update to 1.5.2.

## 1.5.2 - 2021-02-18

* With `libmaxminddb` on Windows and `mmdblookup` generally, there were
  instances where the return value of `calloc` was not checked, which could
  lead to issues in low memory situations or when resource limits had been
  set. Reported by cve-reporting. GitHub #252.

## 1.5.1 - 2021-02-18

* The formatting of the manpages has been improved and the script that
  generates them now supports `lowdown` in addition to `pandoc`. Pull request
  by Faidon Liambotis. GitHub #248.