I'm in over my head, so I asked for help. The folks on debian-devel IRC channel advised me to not bump soname and instead attempt an ABI repair. It was supposed to be harmless to gimagereader.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=815056 I'm really not sure what to do at this point. The Debian package is doing exactly what you asked for, unless I made a mistake. https://github.com/tesseract-ocr/tesseract/issues/254