app: guarantee a ConfigEvent for every Window.Configure call

Not only is the client guaranteed a ConfigEvent, but app.Window
can assume that an unsupported decoration change will be corrected
(by a ConfigEvent with Decorated forced to the supported value).

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/os_ios.go

@@ -281,9 +281,7 @@ func (w *window) Configure([]Option) {
 	prev := w.config
 	// Decorations are never disabled.
 	w.config.Decorated = true
-	if w.config != prev {
-		w.w.Event(ConfigEvent{Config: w.config})
-	}
+	w.w.Event(ConfigEvent{Config: w.config})
 }
 
 func (w *window) EditorStateChanged(old, new editorState) {}