Hey there
Most source files contain the "default" copyright-header (also build by a
script in devtools/copyright_header.py), which points out that the MIT
license can be found in the COPYING file or at
http://www.opensource.org/licenses/mit-license.php.

However, the provided link is 1) using http where it could use https, 2)
resulting in a redirect (https://opensource.org/licenses/mit-license.php)
anyway.
I am strongly in favor of using https where possible (I guess there are
many other non-ssl links in the code base, but lets tackle the easier ones
first).

I propose that I
1) create a issue on github,
2) `sed -i` the relevant links,
3) create a PR on github,
4) come back to the mailing list.

This change would affect a few hundred files I guess.

A question remaining is this change would require a
copyright-year-extension (to 2018), too.

An example header can be seen e.g. here
https://github.com/bitcoin/bitcoin/blob/a9a49e6e7e8df13d80a6dc3245ce7ef041942e9b/src/consensus/merkle.cpp#L3

I'd be happy about quick feedback - do not know the culture here, yet.

Have fun
Felix