Don't render gravatars for spam list in admin

[mrmist]

As per ​http://wordpress.org/support/topic/396031?replies=1 it does indeed seem like a waste of resources to pull gravatars based on emails classed as spam. Perhaps they could be removed from that view?

[ocean90]

-1
What about the false positives? Gravatars are a good feature to recognize that it's not spam, because you know it's a friend or someone else.

[nacin]

On initial report, I agreed with the ticket, but I have to agree with ocean90 here. Also, it's inconsistent UI.