BUG/MEDIUM: da: cast the chunk to string.

in fetch mode, the output was incorrect, setting the type to string
explicitally.

This should be backported to all stable versions.

(cherry picked from commit 7df4185f3c0ca87fb1fe47522af452d98e0e36e7)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/src/da.c b/src/da.c
index f5e0135..5549112 100644
--- a/src/da.c
+++ b/src/da.c
@@ -254,6 +254,7 @@
 
 	smp->data.u.str.area = tmp->area;
 	smp->data.u.str.data = tmp->data;
+	smp->data.type = SMP_T_STR;
 
 	return 1;
 }