Repair double node start in message format tests wallet bridge api
requested to merge kudmich/repair_double_node_start_in_message_format_tests_wallet_bridge_api into develop
Message format tests - wallet bridge API checking the methods responsible for displaying data related to witnesses unnecessarily included two nodes. This MR fixes that problem. Also the acceleration time of nodes preparing the environment with a complete list of witnesses has been reduced (from x50 to x10). This change should stabilize this group of tests.