rocksdb: 4.1

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/rocksdb b/src/rocksdb
index add2ac5fb826463e5525a3e3b1a4a1714dfbeffb..3a0bf873b544794b79e67245c775a9e265be8d47 160000 (submodule)
--- a/src/rocksdb
+++ b/src/rocksdb
@@ -1 +1 @@
-Subproject commit add2ac5fb826463e5525a3e3b1a4a1714dfbeffb
+Subproject commit 3a0bf873b544794b79e67245c775a9e265be8d47