message: [move source language] Fix check for invalid field access from a script
  The check for the current module in the resolve_field function was
  unwrapping an Option that is None in the context of a transaction script,
  causing a compiler crash instead of an error message.
  Closes:
  Approved by: sblackshear
diff: @@ -1332,8 +1332,7 @@ fn resolve_field(context: &mut Context, loc: Loc, ty: BaseType, field: &Field) -
  BaseType_::anything(loc)
  }
  sp!(_, Apply(_, sp!(_, ModuleType(m, n)), targs)) => {
  - let current_module = context.current_module.clone().unwrap();
  - if m != current_module {
  + if !context.is_current_module(&m) {
  let msg = format!(
  "Invalid access of field '{}' on '{}::{}'. \
  Fields can only be accessed inside the struct's module",
  