Stellar | back button in Amount screen should get back to original donation page.

[MoeNick]

Describe the bug

I clicked on back from the amount screen and I can still see this URL: https://giveth.io/donate/hand-protocol?chain=stellar
it cause problems on QF errors and users may got confused. It has to go back to teh original donation path which is https://giveth.io/donate/hand-protocol

CC: @maryjaf

[Meriem-BM]

Made a fix for this too @maryjaf if you can check