create xkb context only after wayland connection is established

This prevents memory leaks since the xkb context is not free'ed if the
exception is thrown.

components/pango_windowing/src/display_wayland.cpp

@@ -842,8 +842,6 @@ static const struct wl_registry_listener wregistry_listener = {
 };
 
 WaylandDisplay::WaylandDisplay() {
-    xkb_context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
-
     wdisplay = wl_display_connect(nullptr);
     if (wdisplay == nullptr) {
         throw std::runtime_error("Cannot connect to Wayland compositor!");
@@ -854,6 +852,8 @@ WaylandDisplay::WaylandDisplay() {
 
     wl_display_roundtrip(wdisplay);
 
+    xkb_context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
+
     egl_display = eglGetDisplay((EGLNativeDisplayType)wdisplay);
     if(!egl_display) {
         std::cerr << "Failed to open EGL display" << std::endl;