extend the second placement search to reduce likelihood deduction

Author: trongnhanuit

utils/tools.cpp

@@ -575,8 +575,8 @@ cmaple::Params::Params() {
   threshold_prob = 1e-8;
   mutation_update_period = 25;
   min_taxa_parallel_placement = 1000;
-  num_samples_per_thread = 5;
-  upward_search_extension = 3;
+  num_samples_per_thread = 3;
+  upward_search_extension = 5;
   failure_limit_sample = 5;
   failure_limit_subtree = 4;
   failure_limit_subtree_short_search = 1;