Ensure keepalive isn't used on uwsgi http mode

According to the uwsgi docs [1] for http keepalive there is a separate
option for http keep alive, and just setting connection close isn't
enough. This commit makes sure we disable http keepalive. This will
hopefully fix the random connection issues we get on image uploads to
glance, which uses uwsgi http mode.

[1] http://uwsgi-docs.readthedocs.io/en/latest/HTTP.html#http-keep-alive

Change-Id: Ic5f83c5c93f28b2bd62ca9ac96ca8c87797ea5c9
Closes-Bug: #1701088
diff --git a/lib/apache b/lib/apache
index 25c65fe..35a9e7b 100644
--- a/lib/apache
+++ b/lib/apache
@@ -322,6 +322,7 @@
     iniset "$file" uwsgi http-raw-body true
     iniset "$file" uwsgi http-chunked-input true
     iniset "$file" uwsgi http-auto-chunked true
+    iniset "$file" uwsgi http-keepalive false
 
     enable_apache_mod proxy
     enable_apache_mod proxy_http