libX changed its libnameA.h to libnameB.h

Hello all,

I'm facing a build error causes from graphics/libnsgif that changed
from 0.2.1 to 1.0.0:
-include/libnsgif.h
+include/nsgif.h

Now graphics/imv complains:

../src/backend_libnsgif.c:9:10: fatal error: 'libnsgif.h' file not found
    9 | #include <libnsgif.h>
      |          ^~~~~~~~~~~~
1 error generated.

While I'm looking from upstream recomendation on fix, how do I quick fix it?
Is it possible to rename libnsgif.h -> nsgif.h in source code?

Also googling about this issue didn't get results since most img pkgs
do not have this lib default on.

Thanks,

-- 
Nuno Teixeira
FreeBSD Committer (ports)