Autotools build on Windows tries to link with libtiff when it's not available

[danpla]

Current Behavior

When I build v5.3.1 on Windows under MSYS2 without libtiff, the configure script clearly tells that the library is not available:

checking for tiffio.h... no

Yet, linking tesseract.exe gives an error:

-ltiff: No such file or directory

It looks like the libtiff is unconditionally linked on Windows: https://github.com/tesseract-ocr/tesseract/blob/f1e3697dd4ff6ee3726edc629a2d63b6a9dcade8/Makefile.am#L758-L761