pi-indexer: fix pi-indexer init [inboxdir] call

[evdenis]

In init mode opts.inboxdir is a string. get_inboxdirs() accepts a list. Thus the string is interpreted as a list of chars resulting in get_inboxdirs() returns an empty set. This means a call:

	$ grok-pi-indexer -v init /.../lkml/git/0.git

will always return:

	> Nothing to do.

Fix it by casting a string to a single element list.

Signed-off-by: Denis Efremov [email protected]