MuonRegionSelector: Fix gcc 11 compilation warning.

Check the result of dynamic_cast before dereferencing.

Jenkins please retry a build

This merge request affects 1 package:

• MuonSpectrometer/MuonDetDescr/MuonRegionSelector

This merge request affects 1 file:

• MuonSpectrometer/MuonDetDescr/MuonRegionSelector/src/MuonRegSelCondAlg.cxx

Adding @sutt ,@rosati ,@nkoehler ,@wleight as watchers

added MuonSpectrometer Trigger master review-pending-level-1 labels

CI Result SUCCESS (hash 1e1c605b)

	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 25179]

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

merged

mentioned in commit 752e2c91

added sweep:ignore label