tests: bluetooth: tester: Improve stability of MESH/NODE/TNPT/BV-05-C

IUT is requested to send 2 multi-segmented model messages. In mean time,
third may be sent from Config Model Publication Status may be sent,
which is also segmented. One of the 3 messages will fail to be sent,
but test is passing if it is Status one. Let's increase number of
possible concurrent transmissions to allow all three messages to be
sent.

Signed-off-by: Krzysztof Kopyściński <[email protected]>

Author: KKopyscinski

tests/bluetooth/tester/prj.conf

@@ -45,7 +45,7 @@ CONFIG_BT_MESH_HEALTH_CLI=y
 CONFIG_BT_MESH_FRIEND=y
 CONFIG_BT_MESH_FRIEND_QUEUE_SIZE=32
 CONFIG_BT_MESH_RX_SEG_MAX=13
-CONFIG_BT_MESH_TX_SEG_MSG_COUNT=2
+CONFIG_BT_MESH_TX_SEG_MSG_COUNT=3
 CONFIG_BT_MESH_LPN_POLL_TIMEOUT=100
 CONFIG_BT_MESH_PROVISIONER=y
 CONFIG_BT_MESH_CDB=y