fixes #114

Otherwise biosimulations errors;

```
Multiple objects have the following ids:\n      -
hhpop_0_bioPhys1_membraneProperties_KConductances_KConductance_n_q\n
- hhpop_0_bioPhys1_membraneProperties_NaConductances_NaConductance_h_q\n
  -
  hhpop_0_bioPhys1_membraneProperties_NaConductances_NaConductance_m_q\n
  - hhpop_0_v\n      - time""
```

Otherwise biosimulations errs with:

```
Multiple objects have the following ids:\n      - time
```