Merge branch 'fix-stagediomanager' into 'master'

Fix FileStager errors triggered by LCG_94

See merge request !1453 (merged)

(cherry picked from commit 0f051c1c)

fb5ca660 First workaround to make sure the LHCb tests pass 44660620 Replace xrd with xrdfs. 1ed7d99c StagedIODataManager: add property to disable PFN warning (warning disabled by... 2d6f7a35 Remove unnecessary options.