Update AddressBook.sol

[philip0529]

I am currently following sir cat with the base testnets and had an error in this part.

So I did some research and the solution I found with my error [not found utils/context.sol when i import from openzepplin]

Solution: By replacing: // SPDX-License-Identifier: MIT in the first line with // SPDX-License-Identifier: GPL-3.0

it will remove the error and will be able to continue the tests.

[nostoryworld]

Thank you for this

[philip0529]

Thank you for this

Glad to help~