cli: fix panic with go 1.17.5 or greater

[ishustava]

Fixes #974

Changes proposed in this PR:

• When building the CLI binary with go 1.17.5 or later (it worked with 1.17.2, but I haven't tested versions in-between), there's a segfault. Based on SIGSEGV: segmentation violation code=0x1 - help golang/go#49992, updating golang.org/x/sys module fixes it.

How I've tested this PR:
built cli locally

How I expect reviewers to test this PR:
👀

Checklist:

• Tests added
• CHANGELOG entry added

  HashiCorp engineers only, community PRs should not add a changelog entry.
  Entries should use present tense (e.g. Add support for...)

[t-eckert]

That was fast!

[ndhanushkodi]

thanks!!