devel/gnustep-make: Fix "makeinfo --html" output directory

• Bump PORTREVISION for package change

Since texinfo 7, "makeinfo --html foo.texi" outputs to foo_html/ rather than foo/ which causes build/plist error for some ports.

For example, during
Take x11-toolkits/gnustep-gui for example, it runs "makeinfo --html AppKit.texi" then checks AppKit/ directory

makeinfo --html AppKit.texi; \
if [ -f AppKit/AppKit_toc.html ]; \

then \
  mv AppKit/AppKit.html .; \
  mv AppKit/AppKit_*.html .; \
  rmdir AppKit/AppKit; \
fi

Obtained from: https://github.com/gnustep/tools-make/commit/3ff4ee8a053b85d63cd34f645258902bb0dc6f04