CoolLumiUtilities+LumiBlockComps: Fix crashes on cosmics..

Zero-sized blobs in the input to BunchLumisCondAlg can occur in cosmics data --- don't treat that as an error.

Fix crash if data for a given lumi channel are missing.

See ATLASRECTS-5000.

This merge request affects 2 packages:

• Database/CoolLumiUtilities
• LumiBlock/LumiBlockComps

Adding @ssnyder as watcher

added DQ Database master review-pending-level-1 labels

enabled an automatic merge when the pipeline for 0b2add87 succeeds

CI Result SUCCESS

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available at NICOS MR-24222-2019-06-16-01-22
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 1
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 381]

merged

mentioned in commit 20a5f1f1

added sweep:ignore label