Fixed nullptr crash

src/widgets/label.cpp

@@ -28,7 +28,7 @@ void Label::redraw(std::string_view str, bool forceRedraw)
         !forceRedraw)
         return;
 
-    const auto renderedWidth = tft.drawString(str.data(), m_x, m_y);
+    const auto renderedWidth = str.empty() ? 0 : tft.drawString(str.data(), m_x, m_y);
     const auto renderedHeight = tft.fontHeight();
 
     if (renderedWidth < m_lastWidth)