Bug#847764: Pending fixes for bugs in the prometheus package

[pkg-go-maintainers]

tag 847764 + pending
thanks

Some bugs in the prometheus package are closed in revision
f6c40f3b2defb82b79f3d54d510d1614c8ae06ab in branch 'debian/sid' by
Martín Ferrari

The full diff can be seen at
https://anonscm.debian.org/cgit/pkg-go/packages/prometheus.git/commit/?id=f6c40f3

Commit message:

    Increase the tests timeout again even more for armel. Closes: #847764