Don't make ajax request for provinces if contry value is empty
Cover the case when we don't revert changes

Instead of using undefined variable.
Plus, rename the url variable to a more explicit name.
[BUG FIX - API] Add missing api province route.
Merge pull request #2094 from Joypricecorp/api-address-missing-config

[BUG FIX - API] Add missing api province route.
Merge pull request #2087 from winzou/history

Cover the case when we don't revert changes
Merge pull request #2080 from crevillo/province-choise

Don't make ajax request for provinces if contry value is empty
Skip volume price if was saved as empty, fix volume pricing form
Display 'volume_based' prices on product details
Merge pull request #2097 from stloyd/bugfix/volume_pricing

Skip volume price if was saved as empty, fix volume pricing form