Using the `export=` argument in Slurm_lapply can clash with other variables

[gvegayon]

Doing

seeds <- ...

Slurm_lapply(
  ...,
  export = c("net0", "ergm_cond", "tc", "theta", "seeds")
)

Can result in an error since slurmR writes an object named seeds and tc too. The function should return an error to the user in those cases.