[LyX/master] Include QScreen header to fix compilation with Qt 5.14

[Yuriy Skalko]

commit 2b6b20ff69eb1f839ea827aedd6f24528abadd9b
Author: Yuriy Skalko <yuriy.skalko at gmail.com>
Date:   Fri Mar 10 09:18:59 2023 +0100

    Include QScreen header to fix compilation with Qt 5.14
    
    Needed after e2e1fd6ea9.
---
 src/frontends/qt/GuiApplication.cpp |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/src/frontends/qt/GuiApplication.cpp b/src/frontends/qt/GuiApplication.cpp
index f8a3e76..c316456 100644
--- a/src/frontends/qt/GuiApplication.cpp
+++ b/src/frontends/qt/GuiApplication.cpp
@@ -108,6 +108,7 @@
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 10, 0))
 #include <QRandomGenerator>
 #endif
+#include <QScreen>
 #include <QSessionManager>
 #include <QSettings>
 #include <QSocketNotifier>