civetweb: update max num of threads

Fixes: #10243
cherry-picked upstream fixed into submodule

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

diff --git a/src/civetweb b/src/civetweb
index 439063547d58427efa921296aa7be107182a026c..8a07012185851b8e8be180391866b5995c10ee93 160000 (submodule)
--- a/src/civetweb
+++ b/src/civetweb
@@ -1 +1 @@
-Subproject commit 439063547d58427efa921296aa7be107182a026c
+Subproject commit 8a07012185851b8e8be180391866b5995c10ee93