index.html: Remove link to Google+
index.html: Remove link to Google+

I'm not on Google+ anymore.

Signed-off-by: Alan Orth <c25dd0841d5fa94899de8e3e4e0aaeefb868a1ba@gmail.com>

oguya/mirror.mjanja.co.ke,ilri/hpc.ilri.cgiar.org-mirror