Simple WoW Addon to fix 'strlower' errors.

This is a common error, that I've seen. Instead of resetting my entire UI, I decided to create a simple Addon to squash the error and ensure that the strlower function will not error if nothing is passed to it.

Reference: https://us.forums.blizzard.com/en/wow/t/chatframe-lua-error/47531

While testing this -- perhaps for weeks, because the error doesn't show up that often anymore -- I am not going to upload this to Curse. Until then, you'll need to download this code and install it in your Interface/AddOns directory.

1. Click the "Code" dropdown above.
2. Select "Download ZIP".
3. Extract the resulting ZIP file.
4. Rename the directory wow-StrlowerFixer-master to StrlowerFixer.
5. Copy StrlowerFixer to your Interface\AddOns directory.
6. Reload (/reload) or restart WoW.