fix: missing closing quote

ORStools/proc/directions_points_layer_proc.py

@@ -222,7 +222,7 @@ def sort(f):
                     if len(points) != len(set(points)):
                         raise exceptions.DuplicateError(
                             "There are duplicate points in the input layer. Traveling Salesman Optimization does not allow this.
-                            Either remove the duplicates or deselect Traveling Salesman.                         
+                            Either remove the duplicates or deselect Traveling Salesman."
                         )
 
                     params = get_params_optimize(points, profile, optimization_mode)