Variables not substitude when checking if repository definition changed

This might be a bug or might be a feature... but it is a problem in change detection, for example in this support case changes were not detected after adding variable although actual URL hasn't changed: https://support.atlassian.com/browse/BSP-5496

There are 2 problem areas:

• adding variable to URL doesn't necessarily mean repository is different
• changing value of variable doesn't trigger all 'isRepositoryDifferent' handling