[publish.yml] QA-245: More strict conditions to publish coverage
[publish.yml] QA-245: More strict conditions to publish coverage

Make sure we only publish the coverage when testing both mender client
and meta-mender are master, otherwise we risk publishing coverage for a
custom build from a PR intending to also publish the qemu image.

Commit 30d3053 wasn't enough...

Signed-off-by: Lluis Campos <9244cb41c39addfc5cf236920b776ea2820513d0@northern.tech>

mendersoftware/meta-mender-qemu