Clarify 4/8 bit loading log message
If you enable 4-bit loading, you will get a message that the model is being loaded in 8-bit. This can be a tad confusing. This tiny PR simply distinguishes in the logging between 4-bit and 8-bit loading.
_The documentation is not available anymore as the PR was closed or merged._<|||||>cc @younesbelkada and @SunMarc<|||||>Thanks!