bootstrap.sh permission for arm64

[etranger05]

A minor report about the "bootstrap.sh" file in arm64 branch. I found it doesn't have execute permission. I think it might be better to grant the permission if it is not intended.

And thank you for the 3.1.0-rc2 updates! But I found the arm64 branch is not updated yet.

Let me continue my testing later. :)

[larryk85]

This should be resolved as of v1.0.0-rc1. Also for Arm64 you don't need to checkout any other branch than main.