bindings: fixed warning on unused function

bindings/ruby/rhash.c

@@ -37,20 +37,23 @@ static VALUE rh_update(VALUE self, VALUE msg) {
  Data_Get_Struct(self, struct rhash_context, ctx);
 
  if (TYPE(msg) != T_STRING) {
- msg = rb_obj_as_string(msg); // convert to string
+ msg = rb_obj_as_string(msg); /* convert to string */
  }
 
  rhash_update(ctx, RSTRING_PTR(msg), RSTRING_LEN(msg));
  return self;
 }
 
+/* declaring non-static method to fix a warning on an unused function */
+VALUE rh_update_file(VALUE self, VALUE file);
+
 /**
  * call-seq:
  * rhash.update_file(filename) -> RHash
  * 
  * Updates this <code>RHash</code> with data from given file.
  */
-static VALUE rh_update_file(VALUE self, VALUE file) {
+VALUE rh_update_file(VALUE self, VALUE file) {
  // this function is actually implemented in pure Ruby below
  // this allows us to handle files in platform-independent way
  return self;