[z1950] Do not calculate targets for different effects with same targeting multiple times

Some effects or target-combinations might need exception from the generic rule that calculated targets from one effect are used by other effects with same targets.
This will fix bugs that different random targets for different effects are selected, even when they should be the same.

Signed-off-by: Schmoozerd <schmoozerd@scriptdev2.com>
Signed-off-by: Nighoo <nighoo@gmail.com>

(cleaned version of 6979002)

(based on commit [s1539] - dc91529)