[LyX/master] Use the cached value GuiSelection::selection_supported_

[Vincent van Ravesteijn]

commit 847d1fb2f5829d1a4bb1302b6a9555265796ada9
Author: Vincent van Ravesteijn <v...@lyx.org>
Date:   Tue Apr 29 15:17:07 2014 +0200

    Use the cached value GuiSelection::selection_supported_
    
    That's where it is for.

diff --git a/src/frontends/qt4/GuiSelection.cpp 
b/src/frontends/qt4/GuiSelection.cpp
index 362da4a..fef258c 100644
--- a/src/frontends/qt4/GuiSelection.cpp
+++ b/src/frontends/qt4/GuiSelection.cpp
@@ -39,7 +39,7 @@ GuiSelection::GuiSelection()
 
 void GuiSelection::haveSelection(bool own)
 {
-       if (!qApp->clipboard()->supportsSelection())
+       if (!selection_supported_)
                return;
 
        // Tell qt that we have a selection by setting a dummy selection.