Add Catch I/O Exception to OpenNI2 Viewer
Add Catch I/O Exception to OpenNI2 Viewer

Add catch I/O exception to openni2_viewer sample.
For example, OpenNI2Grabber throws I/O exception when sensor is not
connected.

ipa-rmb/pcl,stefanbuettner/pcl,drmateo/pcl,drmateo/pcl,ipa-rmb/pcl,ipa-rmb/pcl,ipa-rmb/pcl,stefanbuettner/pcl,drmateo/pcl,stefanbuettner/pcl,stefanbuettner/pcl,ipa-rmb/pcl,stefanbuettner/pcl,drmateo/pcl,drmateo/pcl