make openssl output munging more robust

[satta]

Apparently current openssl versions (in this case Debian stable's OpenSSL 3.0.11 19 Sep 2023 (Library: OpenSSL 3.0.11 19 Sep 2023)) output a string that the WEF cert generation script expect to be in uppercase in lowercase:

$ openssl x509 -in ca-cert.pem -noout -sha1 -fingerprint
sha1 Fingerprint=F5:92:6F:9D:FC:2D:B7:45:CE:76:CA:3F:E9:2F:7C:48:15:C0:42:29

which would lead to an invalid subscription manager string like:

Server=HTTPS://server:5985/wsman/,Refresh=14400,IssuerCA=sha1 Fingerprint=F5926F9DFC2DB745CE76CA3FE92F7C4815C04229

to be generated instead of the correct:

Server=HTTPS://server:5985/wsman/,Refresh=14400,IssuerCA=F5926F9DFC2DB745CE76CA3FE92F7C4815C04229

This fix makes the sed operation case-independent to ensure that this is not a breaking issue. There is also a corresponding MR here: https://gitlab.com/nxlog-public/contrib/-/merge_requests/27

[vruello]

Thanks @satta, nice catch 😃