applications: serial_lte_modem: Fix timeouts with nativetls

Default timeout for TCP, TLS and DTS connections is 3 seconds,
which does not account for network issues. Increase timeout
to 30 seconds.

Signed-off-by: Markus Lassila <[email protected]>

Author: MarkusLassila

applications/serial_lte_modem/overlay-native_tls.conf

@@ -38,6 +38,8 @@ CONFIG_MBEDTLS_DTLS=y
 CONFIG_MBEDTLS_SSL_DTLS_CONNECTION_ID=y
 CONFIG_NET_SOCKETS_ENABLE_DTLS=y
 CONFIG_NET_IPV4=y
+# Maximum timeout for TCP, TLS and DTLS connections
+CONFIG_NET_SOCKETS_CONNECT_TIMEOUT=30000
 # Enable AES
 CONFIG_MBEDTLS_AES_C=y
 CONFIG_MBEDTLS_CCM_C=y