message: Fix crash if texture tabs were open when restoring state.
diff: @@ -1649,6 +1649,9 @@ void TextureViewer::textureTab_Changed(int index)
  {
  ToolWindowManagerArea *textureTabs = ui->dockarea->areaOf(ui->renderContainer);
  + if(!textureTabs)
  + return;
  +
  QWidget *w = textureTabs->widget(index);
  if(w)
  @@ -2804,6 +2807,12 @@ void TextureViewer::setPersistData(const QVariant &persistData)
  m_TexDisplay.backgroundColor =
  checker ? FloatVector() : FloatVector(backCol.redF(), backCol.greenF(), backCol.blueF(), 1.0f);
  + ToolWindowManagerArea *textureTabs = ui->dockarea->areaOf(ui->renderContainer);
  + while(textureTabs->count() > 1)
  + textureTabs->removeTab(1);
  +
  + m_LockedTabs.clear();
  +
  updateBackgroundColors();
  ui->dockarea->restoreState(state);
  