Make small sidebar sizing consistent

src/Splitter.cpp

@@ -167,7 +167,7 @@ splitter::calculateSidebarSizes(const QFont &f)
         const auto height = static_cast<double>(QFontMetrics{f}.lineSpacing());
 
         SideBarSizes sz;
-        sz.small         = std::ceil(3.5 * height + height / 4.0);
+        sz.small         = std::ceil(3.8 * height);
         sz.normal        = std::ceil(16 * height);
         sz.groups        = std::ceil(3 * height);
         sz.collapsePoint = 2 * sz.normal;