civetweb: update submodule

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>

diff --git a/src/civetweb b/src/civetweb
index 45da9c5f9052e82a9368b92e9bfb48878fff844f..439063547d58427efa921296aa7be107182a026c 160000 (submodule)
--- a/src/civetweb
+++ b/src/civetweb
@@ -1 +1 @@
-Subproject commit 45da9c5f9052e82a9368b92e9bfb48878fff844f
+Subproject commit 439063547d58427efa921296aa7be107182a026c