chafa: fix build on i386 systems

[aeiouaeiouaeiouaeiouaeiouaeiou]

Description

Can't really check, but the issue mentioned in the comments solved the build on Void Linux i686. It's unclear when the update will be released, but it's worth a try.

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 10.6.8 10K549 x86_64
Xcode 3.2.6 10M2518

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint --nitpick?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@herbygillot for port chafa.