Use HTTPS for a number of URLs in the docs
diff --git a/docs/hazmat/backends/openssl.rst b/docs/hazmat/backends/openssl.rst
index e829798..b48e502 100644
--- a/docs/hazmat/backends/openssl.rst
+++ b/docs/hazmat/backends/openssl.rst
@@ -78,5 +78,5 @@
.. _`OpenSSL`: https://www.openssl.org/
.. _`initializing the RNG`: https://en.wikipedia.org/wiki/OpenSSL#Predictable_keys_.28Debian-specific.29
-.. _`Yarrow`: http://en.wikipedia.org/wiki/Yarrow_algorithm
+.. _`Yarrow`: https://en.wikipedia.org/wiki/Yarrow_algorithm
.. _`Microsoft documentation`: http://msdn.microsoft.com/en-us/library/windows/desktop/aa379942(v=vs.85).aspx