Update to 0.9.52

• While I'm here:
  • Remove USE_OPENSSL: it is not required after libmicrospdy removal
  • Bump PORTREVISION for dependent ports

Changes: https://gnunet.org/git/libmicrohttpd.git/tree/ChangeLog
PR: 216382
Submitted by: Hung-Yi Chen <gaod@hychen.org> (maintainer)