fix usage of ROS_PARALLEL_JOBS (fix #335)
fix usage of ROS_PARALLEL_JOBS (fix #335)

beni55/catkin,harmishhk/catkin,thaddeustaylor/catkin,beni55/catkin,scpeters/catkin,meyerj/catkin,jack-oquin/catkin,jack-oquin/catkin,ros/catkin,shyamalschandra/catkin,jack-oquin/catkin,meyerj/catkin,wkentaro/catkin,thaddeustaylor/catkin,wkentaro/catkin,shyamalschandra/catkin,thaddeustaylor/catkin,ros/catkin,beni55/catkin,asmodehn/catkin,scpeters/catkin,meyerj/catkin,ros/catkin,wkentaro/catkin,asmodehn/catkin,harmishhk/catkin,shyamalschandra/catkin,asmodehn/catkin,scpeters/catkin,harmishhk/catkin