Remove unnecessary tag from Async Object post title

This `em` tag was used to add some special styling on the source blog.
Here, it serves no real purpose.

Change-Id: I51b3632cee4252e3fbea25649dff38d2851e518d
Reviewed-on: https://gerrit.causes.com/22964
Reviewed-by: Greg Hurrell <greg@causes.com>
Tested-by: Joe Lencioni <joe.lencioni@causes.com>