fix simulate preset selection not triggering update

[mwdchang]

Summary

Change the order of variable updates for presets to take effect

Testing

• Select a model with some parameter value variability (with lower/upper bound not equal).
• Hook up model => model-config => simulate
• Run "normal" simulation, then run "fast" simulation, it should be obvious the two runs are different as the former has significantly more samples than the latter.

Fixes: #4848

[Tom-Szendrey]

Nice catch

[YohannParis]

LGTM