Is your feature request related to a problem? Please describe.

I just spent hours trying to debug a 'error: Duplicate key name "type" defined on line ...' error, stopping polybar from running. Turns out the error was having a space after a module declaration.
"[module/date]" is fine, but "[module/date] " is not. This occurs on Ubuntu 18.04 with Plasma

Why does polybar need this feature?

This would prevent many headaches later.

Describe the solution you'd like

Simply either have an appropriately descriptive error message, or have polybar run under this circumstance.

Describe alternatives you've considered

None

Additional context

None