fix(windows): fix file drop handler (#1122)

.changes/windows-drag-drop.md

@@ -0,0 +1,5 @@
+---
+"wry": "patch"
+---
+
+On Windows, fix file drop handler.

src/webview2/mod.rs

@@ -176,15 +176,15 @@ impl InnerWebView {
   ) -> Result<Self> {
     let _ = unsafe { CoInitializeEx(None, COINIT_APARTMENTTHREADED) };
 
-    let file_drop_controller = attributes
-      .file_drop_handler
-      .take()
-      .map(|handler| FileDropController::new(hwnd, handler));
+    let file_drop_handler = attributes.file_drop_handler.take();
 
     let env = Self::create_environment(&web_context, pl_attrs.clone(), &attributes)?;
     let controller = Self::create_controller(hwnd, &env, attributes.incognito)?;
     let webview = Self::init_webview(hwnd, attributes, &env, &controller, pl_attrs)?;
 
+    let file_drop_controller =
+      file_drop_handler.map(|handler| FileDropController::new(hwnd, handler));
+
     Ok(Self {
       hwnd,
       controller,