Describe the bug
Making a thumbnail of an TIFF image using h2non/bimg returns an error since version 8.10.x

To Reproduce
Steps to reproduce the behavior:

• Try to convert a tiff image using bimg. Use this for instance:

testtiff.zip

• You will get the error tiff2vips: TIFF does not contain page 1

Expected behavior
I expected a working thumbnail like in 8.9.x

Actual behavior

• You will get the error tiff2vips: TIFF does not contain page 1

Environment

• OS: Debian Buster
• Vips: 8.10.1 (manually compiled)

Additional context

• Curiously enough it seems to work using vipsthumbnail, so it might be an issue in bimg, although the error seems to suggest otherwise. Let me know if I should file a bugreport there though ;)