rgw: update civetweb submodule sha1 to track ceph-master

Updating the sha1 to track ceph-master which currently updates civetweb to 1.1

Signed-off-by: Abhishek Lekshmanan <abhishek@suse.com>
(cherry picked from commit 823ce0406b6ef543601db74ecc26a67083c95a1e)

diff --git a/src/civetweb b/src/civetweb
index 1433012e72f2b7f8d06750a29310725cd4368f99..321b4eb68e57ad7e1080dbb24ad4c9a6d64567d5 160000 (submodule)
--- a/src/civetweb
+++ b/src/civetweb
@@ -1 +1 @@
-Subproject commit 1433012e72f2b7f8d06750a29310725cd4368f99
+Subproject commit 321b4eb68e57ad7e1080dbb24ad4c9a6d64567d5