Add OpenSSL note

Author: maxvp

src/content/docs/cloudflare-one/connections/connect-devices/user-side-certificates/manual-deployment.mdx

@@ -496,7 +496,7 @@ To use a Cloudflare root certificate with cURL on macOS, [install the certificat
 
 #### cURL on Windows
 
-To use a Cloudflare certificate with the version of cURL preinstalled on Windows or another version that uses the Schannel (WinSSL) backend, [install the certificate to the Windows certificate store](#windows).
+To use a Cloudflare certificate with the version of cURL preinstalled on Windows or another version that uses the Schannel (WinSSL) backend, [install the certificate to the Windows certificate store](#windows). If you use an older or custom version of cURL built with the OpenSSL backend, you will need to [manually configure cURL to use the certificate](#curl).
 
 #### cURL on Linux