message: Fix possible nullptr exception in CacheTabWidget
diff: @@ -46,14 +46,21 @@ CacheTabWidget::CacheTabWidget(QWidget* parent) : QWidget(parent), m_ui(new Ui::
  m_ui->tabWidget->setTabsClosable(true);
  + if (auto* tabButton = m_ui->tabWidget->tabBar()->tabButton(0, QTabBar::RightSide)) {
  // Store default close button size for future use
  - m_defaultTabButtonSize = m_ui->tabWidget->tabBar()->tabButton(0, QTabBar::RightSide)->size();
  + m_defaultTabButtonSize = tabButton->size();
  // Disable closing for L1 caches and add tab
  - m_ui->tabWidget->tabBar()->tabButton(0, QTabBar::RightSide)->resize(0, 0);
  - m_ui->tabWidget->tabBar()->tabButton(1, QTabBar::RightSide)->resize(0, 0);
  + tabButton->resize(0, 0);
  + if (auto* tabButton2 = m_ui->tabWidget->tabBar()->tabButton(1, QTabBar::RightSide)) {
  + tabButton2->resize(0, 0);
  + }
  + }
  +
  #ifdef N_CACHES_ENABLED
  - m_ui->tabWidget->tabBar()->tabButton(m_addTabIdx, QTabBar::RightSide)->resize(0, 0);
  + if (auto* addTabButton = m_ui->tabWidget->tabBar()->tabButton(m_addTabIdx, QTabBar::RightSide)) {
  + addTabButton->resize(0, 0);
  + }
  #endif
  // Filter out scroll events to avoid mouse scrolling creating a bazillion new caches
  