Links do not point to any document

For now we could safely remove these options,
once we have complete documentation it could be added easily.

Change-Id: I15f19c1cee2e2a65190d1780b41bdf406634253e
Closes-bug: #1625015

doc/source/index.rst

@@ -16,7 +16,5 @@ Contents:
 Indices and tables
 ==================
 
-* :ref:`genindex`
-* :ref:`modindex`
 * :ref:`search`