Bug#919755: libimagequant doesn't use the baseline on i386

[Matthias Klose]

Package: src:libimagequant
Version: 2.12.1-2
Severity: serious
Tags: sid buster

the package is built using -DUSE_SSE=1 -msse -mfpmath=sse on i386, which is not
the i386 baseline.