Fiedler simulated data does not match measurements

The [simulatedData](https://github.com/Benchmarking-Initiative/Benchmark-Models-PEtab/blob/e1cec4af1f674db99acd4548ff3c0768b1ae0f70/Benchmark-Models/Fiedler_BMCSystBiol2016/simulatedData_Fiedler_BMCSystBiol2016.tsv) has observables `pErk_20140430`, `pErk_20140505`, etc., whereas the measurementData and observables files only have the observables `pErk` and `pMek`.