bpo-25910: Fixes redirection from http to https (#4674)

diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst
index 1bd800b..2e56fbc 100644
--- a/Doc/faq/design.rst
+++ b/Doc/faq/design.rst
@@ -343,7 +343,7 @@
 random moments.  Therefore, a complete threads implementation requires thread
 support for C.
 
-Answer 2: Fortunately, there is `Stackless Python <http://www.stackless.com>`_,
+Answer 2: Fortunately, there is `Stackless Python <https://bitbucket.org/stackless-dev/stackless/wiki/Home>`_,
 which has a completely redesigned interpreter loop that avoids the C stack.