Add guard to prevent segfault on Windows
Add guard to prevent segfault on Windows

MouseEvents are thrown when creating the application, before creating the widgets, which cause a segfault when trying to access to the (uninitialized) m_camera pointer.

Zouch/Radium-Engine,AGGA-IRIT/Radium-Engine,AGGA-IRIT/Radium-Engine,Zouch/Radium-Engine