This rule is triggered on any lines that end with whitespace. To fix this,
find the line that is triggered and remove any trailing spaces from the end.
The brspaces parameter allows an exception to this rule for a specific amount
of trailing spaces used to insert an explicit line break/br element. For
example, set brspaces to 2 to allow exactly 2 spaces at the end of a line.
Note: you have to set brspaces to 2 or higher for this exception to take
effect - you can't insert a br element with just a single trailing space, so
if you set brspaces to 1, the exception will be disabled, just as if it was
set to the default of 0.