Qt: fix EPG dialog on HiDpi

(cherry picked from commit 1ec8c36705246b191053b6ebec1491c121cf521a)
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

modules/gui/qt4/components/epg/EPGChannels.cpp

@@ -72,7 +72,7 @@ void EPGChannels::paintEvent( QPaintEvent *event )
             text = text.left( i_idx_channel );
 
         p.drawText( 0, - m_offset + ( i++ + 0.5 ) * TRACKS_HEIGHT - 4,
-                    width(), 20, Qt::AlignLeft, text );
+                    width(), height(), Qt::AlignLeft, text );
 
         int i_width = fontMetrics().width( text );
         if( width() < i_width )

modules/gui/qt4/components/epg/EPGRuler.cpp

@@ -36,8 +36,8 @@ EPGRuler::EPGRuler( QWidget* parent )
     : QWidget( parent )
 {
     setContentsMargins( 0, 0, 0, 0 );
-    setMinimumHeight( 15 );
-    setMaximumHeight( 15 );
+    setMinimumHeight( height() );
+    setMaximumHeight( height() );
     m_offset = 0;
 }