When the SST log archive directory cannot be created or is not writable,
the path is set to an empty string and a warning is logged.
Unfortunately, the warning is logged only after the path has been changed,
so, the following message is displayed:
> WSREP_SST: [WARNING] The '' directory is not writtable
This commit swaps the order of logging and clearing the path so that the
failing path is logged. The new output is:
> WSREP_SST: [WARNING] The '/tmp/something_invalid' directory is not writable
22c8a7b865