output SMESH version number in about dialog

- in order to get this info when user reports bugs

src/Gui/Splashscreen.cpp

@@ -21,6 +21,7 @@
  ***************************************************************************/
 
 #include "PreCompiled.h"
+
 #ifndef _PreComp_
 # include <cstdlib>
 # include <QApplication>
@@ -590,7 +591,7 @@ void AboutDialog::showLibraryInformation()
     li.name = QLatin1String("Salome SMESH");
     li.href = baseurl + QLatin1String("#_TocSalomeSMESH");
     li.url = QLatin1String("https://salome-platform.org");
-    li.version.clear();
+    li.version = QLatin1String(SMESH_VERSION_STR);
     libInfo << li;
 
     // Shiboken