fix(libsinsp/k8s): set api url path to "apps/v1"

The k8s client used "extensions/v1beta1" as api url path in order to
get metadata for daemonsets, deployments and replicasets. Starting with the
v1.16 release of k8s the above mentioned k8s resources are no more served in
"extensions/v1beta1" and are now served in "apps/v1" api version. The
"apps/v1" api version is available since v1.9 of k8s.

Signed-off-by: Aldo Lacuku <[email protected]>

userspace/libsinsp/sinsp.cpp

@@ -2367,7 +2367,7 @@ void sinsp::k8s_discover_ext()
 				}
 				if(uri(*m_k8s_api_server).is_secure()) { init_k8s_ssl(m_k8s_api_cert); }
 				m_k8s_ext_handler.reset(new k8s_api_handler(m_k8s_collector, *m_k8s_api_server,
-									    "/apis/extensions/v1beta1", "[.resources[].name]",
+									    "/apis/apps/v1", "[.resources[].name]",
 									    "1.1", m_k8s_ssl, m_k8s_bt, true));
 				g_logger.log("K8s API extensions handler: collector created.", sinsp_logger::SEV_TRACE);
 			}