Utils: Remove std::initializer_list contructor

If you write

Utils::SmallStringView view;
Utils::SmallString text{view};

it selects the std::initializer_list contructor. Not the didicated
constructore. It is much to easy to get it wrong so it is better
to make it explicit.

Change-Id: I4240eaf1f39cf71d37df4480fea1ecfa3ea83cb0
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/libs/utils/smallstring.h

@@ -152,14 +152,7 @@ public:
              >
     BasicSmallString(BeginIterator begin, EndIterator end)
         : BasicSmallString(&(*begin), size_type(end - begin))
-    {
-    }
-
-    BasicSmallString(std::initializer_list<SmallStringView> list)
-        : m_data(Internal::StringDataLayout<Size>())
-    {
-        appendInitializerList(list, 0);
-    }
+    {}
 
     ~BasicSmallString() noexcept
     {