TrkVertexBilloirTools: Fix out-of-bounds array access.

Eigen indices are 0-based, not 1-based.

This merge request affects 1 package:

• Tracking/TrkVertexFitter/TrkVertexBilloirTools

This merge request affects 1 file:

• Tracking/TrkVertexFitter/TrkVertexBilloirTools/src/FullVertexFitter.cxx

Adding @amorley as watcher

added Tracking master review-pending-level-1 labels

CI Result SUCCESS (hash 29010c2a)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis
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
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 27972]

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

merged

mentioned in commit 73934b39

added sweep:ignore label