civetweb: pull up to ceph-master

Contains the following fixes
- absolute url fixes
- ssl socket closing fixes

Signed-off-by: Abhishek Lekshmanan <abhishek@suse.com>

diff --git a/src/civetweb b/src/civetweb
index cc13125c960cbc967860b4b71c37db5cbd142adb..bb99e93da00c3fe8c6b6a98520fb17cf64710ce7 160000 (submodule)
--- a/src/civetweb
+++ b/src/civetweb
@@ -1 +1 @@
-Subproject commit cc13125c960cbc967860b4b71c37db5cbd142adb
+Subproject commit bb99e93da00c3fe8c6b6a98520fb17cf64710ce7