Fix Dockerfile if statement

[FalcoXYZ]

Fixes

Changes:

Fixes the if statement in the Dockerfile to correct amd64 not building.

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Other (please describe):

Testing

Requires testing

• Yes
• No

In case you checked yes, did you write tests??

• Yes
• No

I've tested this on the following architectures + ubuntu verisons:

PRETTY_NAME="**Ubuntu 20.04.4** LTS"
Linux localhost 5.4.0-109-generic #123-Ubuntu SMP Fri Apr 8 09:10:54 UTC 2022 **x86_64 x86_64 x86_64** GNU/Linux

PRETTY_NAME="**Ubuntu 22.04** LTS"
Linux localhost 5.15.0-27-generic #28-Ubuntu SMP Thu Apr 14 04:55:28 UTC 2022 **x86_64 x86_64 x86_64** GNU/Linux

PRETTY_NAME="**Ubuntu 20.04.4** LTS"
Linux 5.13.0-1022-aws #24~20.04.1-Ubuntu SMP Thu Apr 7 22:14:11 UTC 2022 **aarch64 aarch64 aarch64** GNU/Linux

PRETTY_NAME="**Ubuntu 22.04** LTS"
Linux 5.15.0-1004-aws #6-Ubuntu SMP Thu Mar 31 09:49:20 UTC 2022 **aarch64 aarch64 aarch64** GNU/Linux

All builds succeeded without errors, containers boot up and started syncing + connected to peers. Restarting the container also worked and didn't show any errors. @AntiD2ta can you test this once more to make sure it works before we merge this? Or maybe you can run the pipeline on my branch to verify it works properly?