FreeBSD .so are not recognized as shared objects, so ldd throws an error.  Since there's not really a need to check the dependencies of an .so (use-case is we loaded all the deps from an exe via ldd), don't do it.
Better fallback
Merge branch 'elf-dont-load-dyn-dependencies' of https://github.com/zachriggle/pwntools into zachriggle-elf-dont-load-dyn-dependencies
Replaced a generic "except:" in elf.py with a catching a specific exception
Merge branch 'zachriggle-elf-dont-load-dyn-dependencies'