Use _fontAscent, since we already have it.

Thanks to Maximiliano Curia for spotting it.

src/TerminalDisplay.cpp

@@ -856,9 +856,9 @@ void TerminalDisplay::drawCharacters(QPainter& painter,
         painter.setLayoutDirection(Qt::LeftToRight);
 
         if (_bidiEnabled) {
-            painter.drawText(rect.x(), rect.y() + QFontMetrics(font).ascent(), text);
+            painter.drawText(rect.x(), rect.y() + _fontAscent, text);
         } else {
-            painter.drawText(rect.x(), rect.y() + QFontMetrics(font).ascent(), LTR_OVERRIDE_CHAR + text);
+            painter.drawText(rect.x(), rect.y() + _fontAscent, LTR_OVERRIDE_CHAR + text);
         }
     }
 }