Remove strange line from "config/configure.ac_scripts/end"

The line is "AS_DIRNAME([/* automatically generated */], $ac_prefix_conf_OUT)".

The autoconfig documentation says this should get the directory name of
        "/* automatically generated */"
which obviously is not a file...

Instead I think it attempts to get the dirname of everything in the glob
"/*", i.e. everything in your root dir. Depending on the version of
autotools this either gives an error or a (long) list of "/"s.

It can't possibly be doing anything useful because the result of the macro
isn't assigned to a variable. So I removed it.