CfgGetter syntax fixes for Charginos and Gauginos packages

An issue with the `CfgGetter` syntax for these two packages
was found in the `20.20.X.Y-VAL` nightlies. This commit
pulls in the fixes from `Charginos-00-02-05` and `Gauginos-00-02-03`.
See the discussions in ATLMCPROD-4978. This is also
relevant to ATLASSIM-3401.


Former-commit-id: 00e37ab1849d0225a1d5ae2d1511eb228175271e