Fix resize event on X11. Without this change, resizing window larger than initial size doesn't work.

src/x11/ffi.rs

@@ -1337,6 +1337,23 @@ pub struct XButtonEvent {
     pub same_screen: Bool,
 }
 
+#[repr(C)]
+pub struct XConfigureEvent {
+    pub type_: libc::c_int,
+    pub serial: libc::c_ulong,
+    pub send_event: Bool,
+    pub display: *mut Display,
+    pub event: Window,
+    pub window: Window,
+    pub x: libc::c_int,
+    pub y: libc::c_int,
+    pub width: libc::c_int,
+    pub height: libc::c_int,
+    pub border_width: libc::c_int,
+    pub above: Window,
+    pub override_redirect: Bool,
+}
+
 #[repr(C)]
 pub struct XF86VidModeModeInfo {
     pub dotclock: libc::c_uint,