Moved prototype for static function out of header file to prevent warnings.

src/core/android/SDL_android.cpp

@@ -50,6 +50,8 @@ extern "C" {
 
 /* Implemented in audio/android/SDL_androidaudio.c */
 extern void Android_RunAudioThread();
+
+static void Android_JNI_ThreadDestroyed(void*);
 } // C
 
 /*******************************************************************************

src/core/android/SDL_android.h

@@ -62,7 +62,6 @@ int Android_JNI_GetPowerInfo(int* plugged, int* charged, int* battery, int* seco
 
 /* Threads */
 #include <jni.h>
-static void Android_JNI_ThreadDestroyed(void*);
 JNIEnv *Android_JNI_GetEnv(void);
 int Android_JNI_SetupThread(void);