nullable pay and state url

[AlexKratky]

https://redmine.havelholding.cz/issues/4949

Not sure if this is considered as Breking change. Developers should not use this on subscription payments, but I guess someone 100% does not check if payment is subscription or not :D

[Triplkrypl]

Not sure if this is considered as Breking change.

This is break change, if any one expect only string in return type, and we add null, somewhere can app crash on incompatible type.
@tymajiri will we try make another solution without break changes, or we hope than other developers or ThePay clients will be merciful to us, if we will fucked up some integration?

[tymajiri]

Not sure if this is considered as Breking change.

This is break change, if any one expect only string in return type, and we add null, somewhere can app crash on incompatible type. @tymajiri will we try make another solution without break changes, or we hope than other developers or ThePay clients will be merciful to us, if we will fucked up some integration?

Leda že bychom předávali prázdný string, ale to si nejsem jist zda je lepší 🤨