[LyX/master] Fix bug #10119

[Guillaume Munch]

commit ab41c1d1ac3a54b39b7b5ba630d172ee4bd65049
Author: Guillaume Munch <g...@lyx.org>
Date:   Wed Jun 1 18:27:36 2016 +0100

    Fix bug #10119
    
    This makes Qt 5.4 as usable as Qt 5.5.1 in my experience. Otherwise, fix 
again
    INSTALL.

diff --git a/src/frontends/qt4/GuiWorkArea.cpp 
b/src/frontends/qt4/GuiWorkArea.cpp
index 2bd7c8e..a18294e 100644
--- a/src/frontends/qt4/GuiWorkArea.cpp
+++ b/src/frontends/qt4/GuiWorkArea.cpp
@@ -733,7 +733,7 @@ bool GuiWorkArea::event(QEvent * e)
                        || (ke->key() == Qt::Key_Backtab && (
                                ke->modifiers() == Qt::ShiftModifier
                                || ke->modifiers() == Qt::NoModifier))) {
-                       keyPressEvent(ke);
+                       e->accept();
                        return true;
                }
                return QAbstractScrollArea::event(e);