gensa update breaks

[mb706]

The example in the README.md uses GenSA but fails with the very new version that will probably end up on CRAN soon:

> library("bbotk")
Loading required package: paradox
> fun = function(xs) {
  - (xs[[1]] - 2)^2 - (xs[[2]] + 3)^2 + 10
}

# set domain
domain = ps(
  x1 = p_dbl(-10, 10),
  x2 = p_dbl(-5, 5)
)

# set codomain
codomain = ps(
  y = p_dbl(tags = "maximize")
)

# create Objective object
objective = ObjectiveRFun$new(
  fun = fun,
  domain = domain,
  codomain = codomain,
  properties = "deterministic"
)

# Define termination criterion
terminator = trm("evals", n_evals = 10)

# create optimization instance
instance = OptimInstanceSingleCrit$new(
  objective = objective,
  terminator = terminator
)

# load optimizer
optimizer = opt("gensa")

# trigger optimization
optimizer$optimize(instance)
INFO  [13:49:59.346] [bbotk] Starting to optimize 2 parameter(s) with '<OptimizerGenSA>' and '<TerminatorEvals> [n_evals=10, k=0]'
Error in GenSA::GenSA(par = NULL, fn = inst$objective_function, lower = inst$search_space$lower,  : 
  Trace mat has to be activated to have no improvment stop criteria to work.

the gensa 1.1.11 found here: https://cran.r-project.org/incoming/archive/

[mb706]

problem is this

https://github.com/mlr-org/bbotk/blob/d5530698fb5034f86ce838af6b2476f55573edce/R/OptimizerGenSA.R#L84

[be-marc]

Thanks. Fixed by #215.