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

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39745 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/mediactrl_am.cpp

@@ -64,9 +64,9 @@
     #include "wx/log.h"
     #include "wx/dcclient.h"
     #include "wx/timer.h"
+    #include "wx/math.h"        // log10 & pow
 #endif
 
-#include "wx/math.h"        // log10 & pow
 #include "wx/msw/private.h" // user info and wndproc setting/getting
 #include "wx/dynlib.h"
 #include "wx/stopwatch.h"