fix some warnings

src/main/jni/Application.mk

@@ -1,4 +1,4 @@
 APP_ABI      			:= armeabi x86
 APP_PLATFORM 			:= android-9
 APP_STL      			:= stlport_static
-NDK_TOOLCHAIN_VERSION 	:= 4.8
+NDK_TOOLCHAIN_VERSION 	:= 4.6

src/main/jni/badvpn/lwip/src/include/lwip/arch.h

@@ -32,6 +32,8 @@
 #ifndef __LWIP_ARCH_H__
 #define __LWIP_ARCH_H__
 
+#include "arch/cc.h"
+
 #ifndef LITTLE_ENDIAN
 #define LITTLE_ENDIAN 1234
 #endif
@@ -40,8 +42,6 @@
 #define BIG_ENDIAN 4321
 #endif
 
-#include "arch/cc.h"
-
 /** Temporary: define format string for size_t if not defined in cc.h */
 #ifndef SZT_F
 #define SZT_F U32_F