[ROS Lunar] many gcc warning

[130s]

Reported on ROS buildfarm (thanks to ros/rosdistro#14554 (comment) by @mikaelarguedas):

openni_device.cpp:59, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload

openni_device.cpp:63, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload

openni_device.cpp:67, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload

openni_device.cpp:97, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload

openni_device.cpp:101, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload

openni_device.cpp:663, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload

openni_device_oni.cpp:54, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::OpenFileRecording’ declared with attribute warning: This function is deprecated: Use other overload!

openni_driver.cpp:229, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::Shutdown’ declared with attribute warning: This function is deprecated: You may use Release() instead, or count on dtor

openni_driver.cpp:239, GNU C Compiler 4 (gcc), Priority: Normal
call to ‘xn::Context::CreateProductionTree’ declared with attribute warning: This function is deprecated: Please use other overload