util/wrap.pl: use the apps/openssl.cnf from the source tree

util/wrap.pl: use the apps/openssl.cnf from the source tree

The `make install_fips` target failed

    msp@debian:~/src/openssl$ make install_fips
    *** Installing FIPS module
    install providers/fips.so -> /opt/openssl-dev/lib/ossl-modules/fips.so
    *** Installing FIPS module configuration
    fipsinstall /opt/openssl-dev/ssl/fipsmodule.cnf
    FATAL: Startup failure (dev note: apps_startup()) for ./apps/openssl
    ... No such file or directory:crypto/conf/conf_def.c:771:calling stat(fipsmodule.cnf)
    ...
    make: *** [Makefile:3341: install_fips] Error 1

because the `openssl fipsinstall` command was loading a previously installed
configuration file instead of the copy shipped with the source tree.

    msp@debian:~/src/openssl$ strace -f make install_fips |& grep openssl.cnf
    [pid 128683] openat(AT_FDCWD, "/opt/openssl-dev/ssl/openssl.cnf", O_RDONLY) = 3

This issue reveiled a more general problem, which applies to the tests as well:
unless openssl is installed, the openssl app must not use any preinstalled
configuration file. This holds in particular when the preinstalled configuration
file load providers, which caused the above failure.

The most consistent way to achieve this behaviour is to set the OPENSSL_CONF
environment variable to the correct location in the util/wrap.pl perl wrapper.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14136)