library: Fix NULL pointer dereference
library: Fix NULL pointer dereference

This may be seen when calling stoken_import_rcfile() through the library
interface.  It was introduced with the new v3 token support code.

Signed-off-by: Kevin Cernekee <3105dbb3dd63fbb4f6371cfb04adc6726f76c56b@gmail.com>

mtmiller/stoken,cernekee/stoken,cernekee/stoken,cernekee/stoken,mtmiller/stoken,cernekee/stoken,mtmiller/stoken,mtmiller/stoken