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.
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;
 }