qt5: https mirror

(probably best to kill the bot for this update, referring to #40329 (comment))

Closes #40406.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Formula/qt5.rb

@@ -12,7 +12,7 @@ def message; <<-EOS.undent
 class Qt5 < Formula
   homepage "https://www.qt.io/"
   url "https://download.qt.io/official_releases/qt/5.4/5.4.2/single/qt-everywhere-opensource-src-5.4.2.tar.xz"
-  mirror "http://qtmirror.ics.com/pub/qtproject/official_releases/qt/5.4/5.4.2/single/qt-everywhere-opensource-src-5.4.2.tar.xz"
+  mirror "https://www.mirrorservice.org/sites/download.qt-project.org/official_releases/qt/5.4/5.4.2/single/qt-everywhere-opensource-src-5.4.2.tar.xz"
   sha256 "8c6d070613b721452f8cffdea6bddc82ce4f32f96703e3af02abb91a59f1ea25"
 
   bottle do