In reply to Clive.
In fact, this is your culprit:
http://asociaciongirasol.com/wp-content/uploads/giro.jpg

Change that URL call to httpS where it’s called (header) and the SSL should be fine.
That tool is even more explicit than my initial suggestion:

https://www.whynopadlock.com/

Test at https://www.whynopadlock.com/results/1f63cd52-cec8-45f0-98a6-ef41ec399e6c