[Bug-gnucap] gnucap fails at start due to " ^ ? gnucap-default-plugins.so: cannot open shared object file: No such file or directory"

[Karl-Philipp Richter]

Hi,
After building and installing `gnucap` with `./configure && make && sudo
make install && sudo ldconfig` starting `gnucap` fails due to

    $ gnucap
    Gnucap : The Gnu Circuit Analysis Package
    Never trust any version less than 1.0
    Copyright 1982-2013, Albert Davis
    Gnucap comes with ABSOLUTELY NO WARRANTY
    This is free software, and you are welcome
    to redistribute it under the terms of
    the GNU General Public License, version 3 or later.
    See the file "COPYING" for details.
    main version: master 2016.07.24
    core-lib version: master 2016.07.24
    load gnucap-default-plugins.so
         ^ ? gnucap-default-plugins.so: cannot open shared object file:
No such file or directory
    terminate called after throwing an instance of 'Exception_CS'
    Abgebrochen (Speicherabzug geschrieben)

experienced with 20160724 (according to `git describe --tags`)

-Kalle