[DiapDealer]

The script is correct already (except for the extra #!/bin/sh line at the very end). If you exclusively use the launch script to start Sigil (and never the binary in /usr/lib/sigil) it should work. It works for everyone one else using the distro version of Sigil (without an ld.so.conf.d entry).

Are you perhaps using a shortcut to launch Sigil that points directly to the binary in /usr/lib/sigil instead of the launch script in /usr/bin? Sigil should never be launched with anything other than the script in /usr/bin under normal circumstances.