[AGENT-14947] Fix AttributeError in fetch_intermediate_certs to use http.tls_config (#21851)

* Fix AttributeError in fetch_intermediate_certs: use http.tls_config

* update changelog for fix from 21851

Author: Janaeq

tls/changelog.d/21851.fixed

@@ -0,0 +1 @@
+Fix AttributeError in fetch_intermediate_certs

tls/datadog_checks/tls/tls_remote.py

@@ -179,7 +179,7 @@ def fetch_intermediate_certs(self):
 
         with sock:
             try:
-                context = create_ssl_context(ChainMap({'tls_verify': False}, self.agent_check.tls_config))
+                context = create_ssl_context(ChainMap({'tls_verify': False}, self.agent_check.http.tls_config))
 
                 with context.wrap_socket(sock, server_hostname=self.agent_check._server_hostname) as secure_sock:
                     der_cert = secure_sock.getpeercert(binary_form=True)