Fix window maximize error message appearing when starting the web editor

An error message is no longer printed when trying to maximize the window
in HTML5. This behavior is consistent with Android and iOS.

platform/javascript/os_javascript.cpp

@@ -134,7 +134,6 @@ Size2 OS_JavaScript::get_window_size() const {
 }
 
 void OS_JavaScript::set_window_maximized(bool p_enabled) {
-	WARN_PRINT_ONCE("Maximizing windows is not supported for the HTML5 platform.");
 }
 
 bool OS_JavaScript::is_window_maximized() const {