It's just a symlink, if you know how to use the ln command, you should easily be able to revert the changes. If worst comes to worst, you can just remove libpng from your package manager, then re-add it.
I don't know of anyway to add a specific library file to CMake (doesn't mean there isn't a way though). Usually it just pings the symlink which redirects it to whatever shared object it needs.
I don't know of anyway to add a specific library file to CMake (doesn't mean there isn't a way though). Usually it just pings the symlink which redirects it to whatever shared object it needs.