Nullptr safety.

3d-viewer/3d_canvas/board_adapter.cpp

@@ -368,7 +368,7 @@ void BOARD_ADAPTER::InitSettings( REPORTER* aStatusReporter, REPORTER* aWarningR
     m_biuTo3Dunits = RANGE_SCALE_3D / std::max( m_boardSize.x, m_boardSize.y );
 
     // Hack to keep "home" zoom from being too small.
-    if( !m_board->IsFootprintHolder() )
+    if( !m_board || !m_board->IsFootprintHolder() )
         m_biuTo3Dunits *= 1.6f;
 
     m_boardBodyThickness3DU        = DEFAULT_BOARD_THICKNESS      * m_biuTo3Dunits;