Include wx/app.h according to precompiled headers of wx/wx.h (with other minor cleaning).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38945 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/mediactrl.cpp

@@ -30,9 +30,9 @@
 
 #ifndef  WX_PRECOMP
     #include "wx/log.h"             // wxLogDebug/wxLogSysError/wxLogTrace
+    #include "wx/app.h"             // wxTheApp->argc, wxTheApp->argv
 #endif
 
-#include "wx/app.h"                 // wxTheApp->argc, wxTheApp->argv
 #include "wx/thread.h"              // wxMutex/wxMutexLocker
 #include "wx/timer.h"               // wxTimer