Call of set_opt_map() breaks experiment for further simulations

[kepack]

Utilizing an experiment object for an optimization task (C1), a call to the function 'set_opt_map()' with a single gate inside, i.e. exp.set_opt_map("rx90p[0]") seems to break/change something in the experiment object in a way that one is not able to utilize the same experiment object anymore to do i.e. the simulation of an ORBIT seq.