http: use correct http.sslAutoClientCert setting name

We had been incorrectly looking for the `sslAutoClientCert` Git config
option under the `credential` section, rather than `http`.

Note: this is a Git for Windows only option.

Signed-off-by: Matthew John Cheetham <mjcheetham@outlook.com>

Author: mjcheetham

src/shared/Core/Settings.cs

@@ -659,7 +659,7 @@ public bool IsCertificateVerificationEnabled
         }
 
         public bool AutomaticallyUseClientCertificates =>
-            TryGetSetting(null, KnownGitCfg.Credential.SectionName, KnownGitCfg.Http.SslAutoClientCert, out string value) && value.ToBooleanyOrDefault(false);
+            TryGetSetting(null, KnownGitCfg.Http.SectionName, KnownGitCfg.Http.SslAutoClientCert, out string value) && value.ToBooleanyOrDefault(false);
 
         public string CustomCertificateBundlePath =>
             TryGetPathSetting(KnownEnvars.GitSslCaInfo, KnownGitCfg.Http.SectionName, KnownGitCfg.Http.SslCaInfo, out string value) ? value : null;