Fixes ndk_include_dir on lxml (#2495)

Author: misl6

pythonforandroid/recipes/lxml/__init__.py

@@ -51,10 +51,8 @@ def get_recipe_env(self, arch):
         env['LIBS'] += ' -lxml2'
 
         # android's ndk flags
-        ndk_lib_dir = arch.ndk_lib_dir
-        ndk_include_dir = self.ndk_include_dir
-        cflags += ' -I' + ndk_include_dir
-        env['LDFLAGS'] += ' -L' + ndk_lib_dir
+        cflags += ' -I' + self.ctx.ndk_include_dir
+        env['LDFLAGS'] += ' -L' + arch.ndk_lib_dir
         env['LIBS'] += ' -lz -lm -lc'
 
         if cflags not in env['CFLAGS']: