removed obsolete isnan and check the integer depth value instead of the float.
removed obsolete isnan and check the integer depth value instead of the float.

personalrobotics/iai_kinect2,MRASL/iai_kinect2,MRASL/iai_kinect2,code-iai/iai_kinect2,ShibataLab/iai_kinect2,personalrobotics/iai_kinect2,code-iai/iai_kinect2,ShibataLab/iai_kinect2,code-iai/iai_kinect2