Solve compilation issue in gcc11 due to struct

This solves a compilation failure in the gcc11/centos7 nightly.

added ACTS bugfix labels

Setting urgent since this breaks a nightly.

/cc @wlampl and @pagessin

added urgent label

This merge request affects 1 package:

• Tracking/Acts/ActsVertexReconstruction

This merge request affects 2 files:

• Tracking/Acts/ActsVertexReconstruction/src/AdaptiveMultiPriVtxFinderTool.cxx
• Tracking/Acts/ActsVertexReconstruction/src/IterativePriVtxFinderTool.cxx

Adding @adye ,@tbold ,@goetz ,@jojungge ,@pagessin ,@cvarni ,@toyamaza as watchers

added Tracking main review-pending-level-1 labels

CI Result SUCCESS (hash 57602543)

	Athena
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-EL9 6486] (remote access info)

Looks all good to me. Approved.

Cheers, L1 shifter

removed review-pending-level-1 label

added review-approved label

merged

mentioned in commit 43e8f120