tauRecTools: Protect against null cluster pointers.

Fixes crash with q220.

This merge request affects 1 file:

• Reconstruction/tauRecTools/src/TauClusterFinder.cxx

Adding @goetz ,@martindl ,@adbailey ,@xiaozhon as watchers

added Reconstruction Tau master review-pending-level-1 labels

CI Result SUCCESS (hash 4ea922bd)

	Athena	AthSimulation	AthGeneration	AnalysisBase
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 23333]

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit d09319a2

added sweep:ignore label