[evol assembly] Error in find_max_fitness_2d if trait value on the boundary

[kunstler]

If one trait is on the boundary assembly generate an error because of the function nmkb in maximize_logspace. As stated in the documentation of dfoptim::nmkb the starting value (of the traits for the optimisation of the fitness) should be stricly between the lower and upper bounds (A starting vector of parameter values. Must be feasible, i.e. lie strictly between
lower and upper bounds.).

see https://github.com/traitecoevo/trait_gradients/issues/38

One solution could be to had an exception handling in 'community_new_types_maximum_fitness ' as it is done for other convergence problem such as

  if (attr(ret, "fitness") < eps_positive_fitness) {
    plant_log_max_fitness(paste0("Best point had nonpositive fitness: ",
                                 attr(ret, "fitness")))
    return(empty(sys, ret))
  }