MainWindow->start detection: fixed error msg on CameraOpenNI2::setExposure when exposure/gain parameters are not available 
MainWindow->start detection: fixed error msg on CameraOpenNI2::setExposure when exposure/gain parameters are not available 

git-svn-id: 5c3bb4a0fea81dff653294223dbc7ab7b926c710@2070 f169173b-cf89-36c8-b27e-44dbe73f0c83

markusgrotz/rtabmap,markusgrotz/rtabmap,srmanikandasriram/rtabmap,markusgrotz/rtabmap,chen0510566/rtabmap,chen0510566/rtabmap,MASKOR/rtabmap,srmanikandasriram/rtabmap,srmanikandasriram/rtabmap,MASKOR/rtabmap,chen0510566/rtabmap,MASKOR/rtabmap