[7.4 rc fix] [doc] clarify when database.yml needs to be updated
Clarify that database.yml should be updated if you are running a MySQL Database. Remove wording that de-emphasises importance of update.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Clarify that database.yml should be updated if you are running a MySQL Database. Remove wording that de-emphasises importance of update.