BUG/MINOR: debug: Remove flags CO_FL_SOCK_WR_ENA/CO_FL_SOCK_RD_ENA

These flags were removed by the commit 03abf2d31 ("MEDIUM: connections: Remove
CONN_FL_SOCK*").

This patch may be backported to 2.0.
diff --git a/contrib/debug/flags.c b/contrib/debug/flags.c
index 1a17c7f..08ca054 100644
--- a/contrib/debug/flags.c
+++ b/contrib/debug/flags.c
@@ -141,10 +141,8 @@
 	SHOW_FLAG(f, CO_FL_CTRL_READY);
 	SHOW_FLAG(f, CO_FL_CURR_WR_ENA);
 	SHOW_FLAG(f, CO_FL_XPRT_WR_ENA);
-	SHOW_FLAG(f, CO_FL_SOCK_WR_ENA);
 	SHOW_FLAG(f, CO_FL_CURR_RD_ENA);
 	SHOW_FLAG(f, CO_FL_XPRT_RD_ENA);
-	SHOW_FLAG(f, CO_FL_SOCK_RD_ENA);
 
 	if (f) {
 		printf("EXTRA(0x%08x)", f);