Revert parallelization on algorithms that are used in the server. Let node do this.

This reverts @6b2bf49 on the server algorithms.

routing_algorithms/alternative_path.hpp

@@ -35,14 +35,10 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <boost/assert.hpp>
 
-#include <tbb/parallel_sort.h>
-
 #include <unordered_map>
 #include <unordered_set>
 
 #include <vector>
-#include <algorithm>
-#include <utility>
 
 const double VIAPATH_ALPHA = 0.10;
 const double VIAPATH_EPSILON = 0.15; // alternative at most 15% longer
@@ -64,7 +60,6 @@ class AlternativeRouting final
         {
         }
 
-
         NodeID node;
         int length;
         int sharing;
@@ -292,7 +287,7 @@ class AlternativeRouting final
                 ranked_candidates_list.emplace_back(node, length_of_via_path, sharing_of_via_path);
             }
         }
-        tbb::parallel_sort(ranked_candidates_list);
+        std::sort(ranked_candidates_list.begin(), ranked_candidates_list.end());
 
         NodeID selected_via_node = SPECIAL_NODEID;
         int length_of_via_path = INVALID_EDGE_WEIGHT;