This patch ensures Qt 5.15 in particular can build with modern compilers

See https://bugreports.qt.io/browse/QTBUG-91909 and https://codereview.qt-project.org/c/qt/qtbase/+/339417
---

diff --git a/src/concurrent/qtconcurrentthreadengine.h b/src/concurrent/qtconcurrentthreadengine.h
index cbd8ad04..4cd5b85 100644
--- a/src/concurrent/qtconcurrentthreadengine.h
+++ b/src/concurrent/qtconcurrentthreadengine.h
@@ -256,8 +256,8 @@
 class ThreadEngineStarter<void> : public ThreadEngineStarterBase<void>
 {
 public:
-    ThreadEngineStarter<void>(ThreadEngine<void> *_threadEngine)
-    :ThreadEngineStarterBase<void>(_threadEngine) {}
+    ThreadEngineStarter(ThreadEngine<void> *_threadEngine)
+        : ThreadEngineStarterBase<void>(_threadEngine) {}

     void startBlocking()
     {