Bug - broken link to GCconnex for current list of approved marketplace products

[huguesfcadets]

Summary

In https://github.com/canada-ca/cloud-guardrails/blob/master/EN/12_Cloud-Marketplace-Config.md, the link to GCconnex for current list of approved marketplace products is broken.

Possible fixes

Link to the group responsible to maintain the list and procedure to have new product added.
Refer to approved cloud marketplaces.