Need to incrementally migrate the remaining places (ODF, OOXML signing)
to CNG, then flip the default. SVL_CRYPTO_CNG=1 is needed till then.

(The testcase passes with and without the fix when SVL_CRYPTO_CNG is not
specified; it fails without the fix when SVL_CRYPTO_CNG is specified.)

Change-Id: Ide9d3b109bbd955a9cb83b18bba6aa72269f4d34
Reviewed-on: https://gerrit.libreoffice.org/55030Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>