Product page update to fix GitHost text

Closed Reb requested to merge 853-EE-githost-text into master

Clarifies GitHost requirements

By changing "EE license required" to "Purchase of Enterprise Edition license required"

  • People unfamiliar with our products may not know that EE means Enterprise Edition
  • Having "You host it" and "We host it" does not make clear that if we host it one of the you host it selections needs to be purchased also.

Related issue in Marketing project: closes https://gitlab.com/gitlab-com/marketing/issues/853