Don't segfault if the first 'auto-key-locate' option is 'clear'.
* g10/getkey.c (free_akl): If AKL is NULL, just return.
Backported from f2ee673c99825d5189631031ddec2dbf54dbd482. Note:
unlike in 2.1, in 2.0 this bug is not (currently) triggered since
parse_auto_key_locate doesn't recognize "clear".
- Signed-off-by: Neal H. Walfield <neal@g10code.com>.
- Reported-by: Sami Farin.
- GnuPG-bug-id: T2045