schannel: make CAinfo parsing resilient to CR/LF

OpenSSL has supported --cacert for ages, always accepting LF-only line
endings ("Unix line endings") as well as CR/LF line endings ("Windows
line endings").

When we introduced support for --cacert also with Secure Channel (or in
cURL speak: "WinSSL"), we did not take care to support CR/LF line
endings, too, even if we are much more likely to receive input in that
form when using Windows.

Let's fix that.

Happily, CryptQueryObject(), the function we use to parse the ca-bundle,
accepts CR/LF input already, and the trailing LF before the END
CERTIFICATE marker catches naturally any CR/LF line ending, too. So all
we need to care about is the BEGIN CERTIFICATE marker. We do not
actually need to verify here that the line ending is CR/LF. Just
checking for a CR or an LF is really plenty enough.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Closes https://github.com/curl/curl/pull/2592