Update raw-window-handle to 0.4.1 (#1957)

* Update raw-window-handle to `0.4.2`

See:
- https://github.com/rust-windowing/raw-window-handle/issues/72
- https://github.com/rust-windowing/raw-window-handle/pull/73
- https://github.com/rust-windowing/raw-window-handle/pull/74

* Clean up raw_window_handle functions a bit

src/platform_impl/linux/x11/window.rs

@@ -1,4 +1,4 @@
-use raw_window_handle::unix::XlibHandle;
+use raw_window_handle::XlibHandle;
 use std::{
     cmp, env,
     ffi::CString,
@@ -1458,10 +1458,9 @@ impl UnownedWindow {
 
     #[inline]
     pub fn raw_window_handle(&self) -> XlibHandle {
-        XlibHandle {
-            window: self.xwindow,
-            display: self.xconn.display as _,
-            ..XlibHandle::empty()
-        }
+        let mut handle = XlibHandle::empty();
+        handle.window = self.xlib_window();
+        handle.display = self.xlib_display();
+        handle
     }
 }