[vte] pty: Only fill in ws_[xy]pixel when sixel is enabled

[Christian Persch <chpe src gnome org>]

commit 2473ddb9eb312cd646ed7c04d75907957e5eb1cf
Author: Christian Persch <chpe src gnome org>
Date:   Sat Aug 22 20:53:10 2020 +0200

    pty: Only fill in ws_[xy]pixel when sixel is enabled

 src/pty.cc | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/pty.cc b/src/pty.cc
index f148b24f..ce77106b 100644
--- a/src/pty.cc
+++ b/src/pty.cc
@@ -294,8 +294,10 @@ Pty::set_size(int rows,
        memset(&size, 0, sizeof(size));
        size.ws_row = rows > 0 ? rows : 24;
        size.ws_col = columns > 0 ? columns : 80;
+#ifdef WITH_SIXEL
         size.ws_ypixel = size.ws_row * cell_height_px;
         size.ws_xpixel = size.ws_col * cell_width_px;
+#endif
        _vte_debug_print(VTE_DEBUG_PTY,
                        "Setting size on fd %d to (%d,%d).\n",
                        master, columns, rows);