log-cleanup tries to delete all files when BASE_LOG_FOLDER is empty string

[bbonagura9]

The code need some workaround to avoid that.

On line 77, line 80 and line 83 the find statements work like:

find ${BASE_LOG_FOLDER}/*/* ...

When BASE_LOG_FOLDER is empty, it searches from /*/* and tries to remove everything. It actually succeeds deleting a lot of stuff.