Issue Loading PPM File

[dichiban]

Hello,

I've been trying to load up a .ppm file with the following code

{% picture images/greyscale.ppm %}

but have been unable to do so as I get the following error message.

/usr/share/gems/gems/ruby-vips-2.0.17/lib/vips/operation.rb:355:in `block in call': unable to call VipsForeignSavePpmFile: unknown option Q (Vips::Error)

This may be due to using an older version of ruby-vips, but am unsure.

Any ideas on where the Q option is coming from?

Using jekyll_picture_tag v2.1.0 vips-8.15.2

[dichiban]

fixed with PR