Fixed bug 2688 - failure to build test/loopwavequeue.c on Linux

test/loopwavequeue.c

@@ -15,12 +15,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "SDL.h"
+
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif
 
-#include "SDL.h"
-
 struct
 {
     SDL_AudioSpec spec;