midnight-commander: use curl -k to download

Closes Homebrew/homebrew#7229.

Signed-off-by: Max Howell <max@methylblue.com>

Formula/midnight-commander.rb

@@ -1,7 +1,16 @@
 require 'formula'
 
+class MidnightCommanderDownloadStrategy < CurlDownloadStrategy
+  # midnight-commander.org uses a self-signed cert, which is
+  # silly and trips curl up
+  def _fetch
+    curl '-k', @url, '-o', @tarball_path
+  end
+end
+
 class MidnightCommander < Formula
-  url 'http://www.midnight-commander.org/downloads/mc-4.7.5.3.tar.bz2'
+  url 'http://www.midnight-commander.org/downloads/mc-4.7.5.3.tar.bz2',
+      :using => MidnightCommanderDownloadStrategy
   homepage 'http://www.midnight-commander.org/'
   sha256 '0875b4c745d771b65ab71d0a295f2e6e91297121411a82068e2879f39a7628b6'