fix: claer CFLAGS and LDFLAGS for openssl product

Author: ahogappa

lib/ruby_wasm/build_system/product/openssl.rb

@@ -64,7 +64,7 @@ def build
       system "./Configure #{configure_args.join(" ")}", chdir: product_build_dir
       # Use "install_sw" instead of "install" because it tries to install docs and it's very slow.
       # OpenSSL build system doesn't have well support for parallel build, so force -j1.
-      system "make -j1 install_sw DESTDIR=#{destdir}", chdir: product_build_dir
+      system "make -j1 install_sw DESTDIR=#{destdir} CNF_CFLAGS='' CNF_LDFLAGS=''", chdir: product_build_dir
     end
   end
 end