fix compilation warning
fix compilation warning

--HG--
extra : transplant_source : %00x%5B%F5f%BDR%AFGL%2Ag7%A4gx%A22%C1%09

davetcoleman/ompl,florianhauer/ompl,florianhauer/ompl,davetcoleman/ompl,utiasASRL/batch-informed-trees,florianhauer/ompl,utiasASRL/batch-informed-trees,florianhauer/ompl,jvgomez/ompl,sonny-tarbouriech/ompl,jvgomez/ompl,davetcoleman/ompl,florianhauer/ompl,jvgomez/ompl,jvgomez/ompl,sonny-tarbouriech/ompl,utiasASRL/batch-informed-trees,sonny-tarbouriech/ompl,sonny-tarbouriech/ompl,sonny-tarbouriech/ompl,davetcoleman/ompl,jvgomez/ompl,davetcoleman/ompl,utiasASRL/batch-informed-trees,davetcoleman/ompl,sonny-tarbouriech/ompl,florianhauer/ompl,jvgomez/ompl,utiasASRL/batch-informed-trees,utiasASRL/batch-informed-trees