Fix XercesC warning silencing when using official FindXercesC

added all-slots cleanup labels

@dmuller FYI

• [2020-01-28 00:07] Validation started with lhcb-gaussino#680
• [2020-01-30 00:11] Validation started with lhcb-gaussino#681
• [2020-01-31 00:07] Validation started with lhcb-gaussino#682
• [2020-02-01 00:06] Validation started with lhcb-gaussino#683
• [2020-02-08 00:06] Validation started with lhcb-gaussino#684
• [2020-02-14 00:06] Validation started with lhcb-gaussino#685
• [2020-02-20 00:07] Validation started with lhcb-gaussino#686
• [2020-02-25 00:07] Validation started with lhcb-gaussino#687
• [2020-02-26 00:09] Validation started with lhcb-gaussino#688
• [2020-02-27 00:09] Validation started with lhcb-gaussino#689
• [2020-02-28 00:06] Validation started with lhcb-gaussino#690
• [2020-03-05 00:06] Validation started with lhcb-gaussino#691
• [2020-03-12 00:08] Validation started with lhcb-gaussino#692
• [2020-03-19 00:11] Validation started with lhcb-gaussino#693
• [2020-03-20 05:05] Validation started with lhcb-gaussino#694
• [2020-03-21 00:06] Validation started with lhcb-gaussino#695
• [2020-03-24 00:10] Validation started with lhcb-gaussino#696
• [2020-03-25 00:11] Validation started with lhcb-gaussino#697
• [2020-03-26 00:08] Validation started with lhcb-gaussino#698
• [2020-03-27 00:09] Validation started with lhcb-gaussino#699
• [2020-03-28 00:10] Validation started with lhcb-gaussino#700
• [2020-03-31 00:10] Validation started with lhcb-gaussino#701
• [2020-04-01 00:06] Validation started with lhcb-gaussino#702
• [2020-04-07 00:09] Validation started with lhcb-gaussino#703
• [2020-04-08 01:13] Validation started with lhcb-gaussino#704
• [2020-04-09 00:06] Validation started with lhcb-gaussino#705
• [2020-04-10 00:12] Validation started with lhcb-gaussino#706
• [2020-04-15 00:14] Validation started with lhcb-gaussino#707
• [2020-04-17 00:06] Validation started with lhcb-gaussino#708
• [2020-04-18 00:07] Automatic merge failed in lhcb-gaussino#709
• [2020-04-21 00:06] Automatic merge failed in lhcb-gaussino#710
• [2020-04-22 00:06] Automatic merge failed in lhcb-gaussino#711
• [2020-04-24 00:13] Automatic merge failed in lhcb-gaussino#712
• [2020-04-25 00:07] Automatic merge failed in lhcb-gaussino#713
• [2020-04-28 00:10] Automatic merge failed in lhcb-gaussino#714
• [2020-04-29 00:12] Automatic merge failed in lhcb-gaussino#715
• [2020-04-30 00:09] Automatic merge failed in lhcb-gaussino#716
• [2020-05-07 00:11] Automatic merge failed in lhcb-gaussino#717
• [2020-05-12 00:11] Automatic merge failed in lhcb-gaussino#718
• [2020-05-13 00:11] Automatic merge failed in lhcb-gaussino#719
• [2020-05-15 00:08] Automatic merge failed in lhcb-gaussino#720

@dmuller this has the desired effect, ready to be merged

assigned to @dmuller

added ~23057 label and removed all-slots label

Change was added to Futurev3 during a rebase ontop of master.

closed

unassigned @dmuller