repmgr: add --terse mode to "cluster show"

This suppresses display of the usually lengthy "conninfo" column, mainly
useful for generating a compact table suitable for pasting into emails,
chats etc. without messy line breaks.

Implements GitHub #521.

repmgr-action-daemon.c

@@ -91,6 +91,7 @@ do_daemon_status(void)
 	for (i = 0; i < STATUS_HEADER_COUNT; i++)
 	{
 		headers_status[i].max_length = strlen(headers_status[i].title);
+		headers_status[i].display = true;
 	}
 
 	i = 0;