Remove redundant TIFF warning handler setup

[kleisauke]

This became redundant after commit libvips/libvips@22994d9.

[lovell]

I was planning to leave this logic in place for a bit longer as some OS and package managers for which prebuilt binaries are not provided e.g. FreeBSD still provide libvips v8.17.0.

[kleisauke]

Isn't that an invalid use case? See for example:

sharp/src/common.h

Lines 17 to 21 in 276ac2d

	#if (VIPS_MAJOR_VERSION < 8) || \
	(VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 17) || \
	(VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION == 17 && VIPS_MICRO_VERSION < 1)
	#error "libvips version 8.17.1+ is required - please see https://sharp.pixelplumbing.com/install"
	#endif

In other words, you can't compile sharp v0.34.3 with libvips v8.17.0.

[lovell]

Ha ha, oh yeah, I try to be an angel to FreeBSD's demon but look what happens! 😅