android: Fix build after updating Linux headers

Since we don't use the kernel-netlink plugin anymore and the headers
in the NDK are reasonably recent, we don't need this anymore (at least
when building the app).

Fixes #1172.

src/libcharon/Android.mk

@@ -228,7 +228,6 @@ endif
 # build libcharon --------------------------------------------------------------
 
 LOCAL_C_INCLUDES += \
-	$(strongswan_PATH)/src/include \
 	$(strongswan_PATH)/src/libhydra \
 	$(strongswan_PATH)/src/libstrongswan
 

src/libhydra/Android.mk

@@ -20,7 +20,6 @@ LOCAL_SRC_FILES += $(call add_plugin, kernel-netlink)
 # build libhydra ---------------------------------------------------------------
 
 LOCAL_C_INCLUDES += \
-	$(strongswan_PATH)/src/include \
 	$(strongswan_PATH)/src/libstrongswan
 
 LOCAL_CFLAGS := $(strongswan_CFLAGS)

src/libipsec/Android.mk

@@ -20,7 +20,6 @@ LOCAL_SRC_FILES := $(filter %.c,$(libipsec_la_SOURCES))
 # build libipsec ---------------------------------------------------------------
 
 LOCAL_C_INCLUDES += \
-	$(strongswan_PATH)/src/include \
 	$(strongswan_PATH)/src/libstrongswan
 
 LOCAL_CFLAGS := $(strongswan_CFLAGS)