Internal hosted UC not supported

We are hosting update center in Nexus which has a self-signed certificate so when I run this command it fails with the following error:

`io.jenkins.tools.pluginmanager.impl.UpdateCenterInfoRetrievalException: Error getting update center json
at io.jenkins.tools.pluginmanager.impl.PluginManager.getJson(PluginManager.java:578)
at io.jenkins.tools.pluginmanager.impl.PluginManager.getUCJson(PluginManager.java:597)
at io.jenkins.tools.pluginmanager.impl.PluginManager.start(PluginManager.java:146)
at io.jenkins.tools.pluginmanager.impl.PluginManager.start(PluginManager.java:113)
at io.jenkins.tools.pluginmanager.cli.Main.main(Main.java:63)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1946)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:316)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:310)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1639)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:223)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1037)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:965)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1064)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1395)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1379)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1570)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:268)
at java.net.URL.openStream(URL.java:1068)
at org.apache.commons.io.IOUtils.toString(IOUtils.java:2795)
at io.jenkins.tools.pluginmanager.impl.PluginManager.getJson(PluginManager.java:572)
... 4 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:450)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:317)
at sun.security.validator.Validator.validate(Validator.java:262)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:330)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:237)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:132)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1621)
... 19 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:445)
... 25 more
Error getting update center json
`

I tried adding our ca certificate to /usr/local/share/certificates and then running update-ca-certificates but it still doesn't work.
Perhaps we need a flag to ignore self-signed certificates eg when using the script I could pass CURL_OPTS -k