Remove very spammy warning message from ExtraParticlesInAcceptance. Port to Sim09-upgrade

Port the changes in branch 'admorris/ExtraParticlesInAcceptance-warning' for 'master' into 'Sim09-upgrade'

See original merge request !502 (merged) for master. Also corresponds to !543 (merged) for Sim09

(cherry picked from commit 9d478005)

• 58d08d02 Remove very spammy warning message for a check that is in the wrong place.
• 9409417f Fixed an extra curly bracket