INTERNALS: specify minimum version for Heimdal: 7.1.0

Released on 2016-Dec-19, it's the first "revamped" stable version, and
the earliest available as a source tarball at the official repository:
https://github.com/heimdal/heimdal/releases/tag/heimdal-7.1.0

It's also the first version hosted by Homebrew. It builds fine locally
with curl, and also builds in CI with old linux: 7.1.0+dfsg-13+deb9u4.

Closes #18809

diff --git a/docs/INTERNALS.md b/docs/INTERNALS.md
index f3c34c1143394f9d3fd408d58116128f38334528..84b939f4dcb46396df67a5967ad60a7f16b2f395 100644 (file)
--- a/docs/INTERNALS.md
+++ b/docs/INTERNALS.md
@@ -36,7 +36,7 @@ versions of libs and build tools.
  - wolfSSL      3.4.6
  - OpenLDAP     2.0
  - MIT Kerberos 1.2.4
- - Heimdal      ?
+ - Heimdal      7.1.0
  - nghttp2      1.15.0
 
 ## Build tools