Trac #29490: fedora-30-standard: Doctests using system brial crash

Follow-up from #29369: I see crashes in running doctests on
`fedora-30-standard` (https://github.com/mkoeppe/sage/runs/572856797),
which uses system brial 1.2.5-1

{{{
sage -t src/sage/rings/polynomial/multi_polynomial_sequence.py  # Killed
due to abort
sage -t src/sage/rings/polynomial/pbori.pyx  # Killed due to abort
sage -t src/sage/rings/polynomial/polynomial_ring_constructor.py  #
Killed due to abort
sage -t src/sage/sat/boolean_polynomials.py  # Killed due to abort
sage -t src/sage/sat/solvers/dimacs.py  # Killed due to abort
}}}

We remove the spkg-configure for Sage 9.1.

A follow up ticket can restore and repair it for 9.2.

URL: https://trac.sagemath.org/29490
Reported by: mkoeppe
Ticket author(s): Matthias Koeppe
Reviewer(s): Dima Pasechnik