[FIX] fix add gateway form (RT-2773)

fix "Save" button always disabled after "Cancel"
Merge pull request #1872 from darkdarkdragon/develop-RT-2773

[FIX] fix add gateway form (RT-2773)
[TASK] Trust: Refactor for better code architecture
[TASK] Fund: Move all tx messages to transactionerror.jade file
[TASK] Fund currency: Put generic error message for non tx-related errors