ci: speed up code-coverage jobs

Plus some documentation updates

Change-Id: I6fd2b04e22bca6c3d6e36e78d1995220e261206b
Refs: #3809
diff --git a/docs/index.rst b/docs/index.rst
index 291fb72..f73ad84 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -5,7 +5,7 @@
 used to implement various NDN applications.
 
 Please submit any bugs or issues to the `ndn-cxx issue tracker
-<http://redmine.named-data.net/projects/ndn-cxx/issues>`__.
+<https://redmine.named-data.net/projects/ndn-cxx/issues>`__.
 
 ndn-cxx Documentation
 ---------------------