fix(XOSAN): ignore error if pack has already been installed (#529)
fix(XOSAN): ignore error if pack has already been installed (#529)

Fixes vatesfr/xo-web#2084
lmcro/xo-web,lmcro/xo-web,vatesfr/xo-web,vatesfr/xo-web,lmcro/xo-web