Crash in the osgfadetext example with OSG 3.6.5

[KimuraRyo]

osgText::FadeText does not work after 356e16e.
Empty FrameStamp is referenced in FadeText::drawImplementation(osg::RenderInfo& renderInfo).
I reproduced this using Visual Studio 2017 on Windows 10.

[openscenegraph]

Thanks for the note. I've investigated and found the crash is due to the compile traversal not assigning a FrameStamp as the code assumes and ends up derefercing a nullptr. I've checked in fixes to master the 3.6 branch:

e4373b0