-ap ONLY mode does not use -at RIGHT vs -at LEFT

[bwlang]

I think -ap ONLY mode should still respect the -at option (to keep RIGHT or LEFT side)

flexbar -n 16 -r 1.fastq.gz -p 2.fastq.gz -av 20 -at RIGHT -ap ONLY  -t trimmed_ends_right -l ALL

and

flexbar -n 16 -r 1.fastq.gz -p 2.fastq.gz -av 20 -at LEFT -ap ONLY  -t trimmed_ends_left -l ALL

produce identical output.

This can be handy for evaluating the trimmed sequences.