remove comment mentioning mutable

Remove an obsolete comment which was triggering certain scripts to assume the code is actually using a not thread safe mutable

Jenkins please retry a build

This merge request affects 1 package:

• Reconstruction/egamma/egammaAlgs

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

CI Result SUCCESS

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available at NICOS MR-22889-2019-04-26-00-07
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST 37625]

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

merged

mentioned in commit cd023f9b

added sweep:ignore label