Update log.lua

[cxwx]

string DEBUG_PLENARY bug
see the ISSUE: justinhj/battery.nvim#55

[delphinus]

Why do you think this is a bug? I think this is an intended behavior.

README says that,

Troubleshooting

If you're having trouble / things are hanging / other problems:

$ export DEBUG_PLENARY=true

This will enable debugging for the plugin.

If you want to see log, then export DEBUG_PLENARY=true. If not, then export DEBUG_PLENARY= (means removing $DEBUG_PLENARY). That's all.

[cxwx]

So, it does not support export DEBUG_PLENARY=true