erlang: 18.3 -> 18.3.4 (#16244)

Minor OTP releases (and their manpages) are not available for dowload at
http://erlang.org/download
But e.g.:
- 18.3.1 contains an important fix for mnesia
- 18.3.1-18.3.4 has a lot of SSL/TLS fixes

So we have to fetch from GitHub and build everything ourselves.

Also replace explicit path patching with upstream patches:
- https://github.com/erlang/otp/pull/1023
- https://github.com/erlang/otp/pull/1103 - with this patch it's now
  possible to build erlang in sandboxed mode