Remove BINARYEN_METHOD in wasm settings.

This was removed according to https://kripken.github.io/emscripten-site/docs/compiling/WebAssembly.html#debugging

BUG=webp:413

Change-Id: If8f1a3f1260d34cdd2b937b286e4c57fb48ed828
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 499ddce..7f4750e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -556,7 +556,7 @@
   target_include_directories(webp_wasm PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
   set_target_properties(
     webp_wasm
-    PROPERTIES LINK_FLAGS "-s WASM=1 -s 'BINARYEN_METHOD=\"native-wasm\"' \
+    PROPERTIES LINK_FLAGS "-s WASM=1 \
        -s EXPORTED_FUNCTIONS='[\"_WebpToSDL\"]' -s INVOKE_RUN=0 \
        -s EXTRA_EXPORTED_RUNTIME_METHODS='[\"cwrap\"]'")
   target_compile_definitions(webp_wasm PUBLIC EMSCRIPTEN WEBP_HAVE_SDL)