Update symmetrization for cov

Merge branch 'master' of gitlab.in2p3.fr:tristram/Xpol

Conflicts:
	xpol/xpol.py
2 jobs for master in 2 minutes and 13 seconds
Status Job ID Name Coverage
  Test
passed #242279
test-3.8

00:01:22

passed #242280
test-3.9

00:02:13