Clarify description of encrypted volume transfer mv
This patch addresses a comment raised in the review of the feature,
@@ -532,4 +532,6 @@ following meanings:
3.70
----
-Add the ability to transfer encrypted volumes and their snapshots.
+Add the ability to transfer encrypted volumes and their snapshots. The feature
+removes a prior restriction on transferring encrypted volumes. Otherwise, the
+API request and response schema are unchanged.
