Remove unnecessary xxSys dependencies

Cherry-picked from !264 (merged) on master

To be cherry-picked also to 2018-patches, 2017-patches, 2016-patches

• [2018-10-27 00:26] Validation started with lhcb-run2-patches#180
• [2018-10-28 00:14] Validation started with lhcb-run2-patches#181
• [2018-10-29 00:15] Validation started with lhcb-run2-patches#182

changed the description

changed the description

merged

mentioned in commit 996b59d8

mentioned in commit cbbb61eb

mentioned in merge request !266 (merged)

mentioned in commit 980c13c1

mentioned in merge request !267 (merged)

mentioned in commit b52be55d

mentioned in merge request !268 (merged)