ci/mqtt: Made MQTT test app tls insecure capable

This is needed for testing different connection modes in the mqtt
library, specifically:
* test case CONFIG_EXAMPLE_CONNECT_CASE_NO_CERT: default server - expect to connect normally

tools/test_apps/protocols/mqtt/publish_connect_test/sdkconfig.ci.default

@@ -7,3 +7,5 @@ CONFIG_MBEDTLS_ASYMMETRIC_CONTENT_LEN=y
 CONFIG_MBEDTLS_SSL_IN_CONTENT_LEN=16384
 CONFIG_MBEDTLS_SSL_OUT_CONTENT_LEN=16384
 CONFIG_ESP_NETIF_TCPIP_ADAPTER_COMPATIBLE_LAYER=n
+CONFIG_ESP_TLS_INSECURE=y
+CONFIG_ESP_TLS_SKIP_SERVER_CERT_VERIFY=y