CONTRIB: debug: add missing flags SF_HTX and SF_MUX

These two were forgotten when HTX was added. They can be backported
as they're missing for debugging traces in 2.0.

(cherry picked from commit 8a0eabd536ca1354e2f24fcb7810042f31751010)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 4d295b261b62930c4b7b470887dddd9c6f40a09a)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/contrib/debug/flags.c b/contrib/debug/flags.c
index 92b9c66..0afdae9 100644
--- a/contrib/debug/flags.c
+++ b/contrib/debug/flags.c
@@ -364,7 +364,9 @@
 	case SF_ERR_CHK_PORT: f &= ~SF_ERR_MASK ; printf("SF_ERR_CHK_PORT%s",       f ? " | " : ""); break;
 	}
 
+	SHOW_FLAG(f, SF_HTX);
 	SHOW_FLAG(f, SF_REDIRECTABLE);
+	SHOW_FLAG(f, SF_IGNORE);
 	SHOW_FLAG(f, SF_REDISP);
 	SHOW_FLAG(f, SF_CURR_SESS);
 	SHOW_FLAG(f, SF_MONITOR);