Test connection - incorrect permission checking for plan-local repositories

Users with WRITE permission to a Bamboo plan can't currently test connection to plan-local repositories. WRITE permission to a plan is sufficient to edit that plan repositories' configuration, and thus should be sufficient to test connection.

Steps to reproduce:
ADMIN:

• create plan
• create plan-local repository
• edit repository configuration: success
• test connection to that repository: success
• create user
• grant user WRITE to that plan

USER:

• edit plan
• edit repository configuration: success (WRITE was sufficient to save changes)
• test connection to that repository - ERROR