Fix URLs when running with tls-proxy enabled

Various services are returning broken links when running behind
tls-proxy. These issues can be fixed by setting the X-Forwarded-Proto
header in the apache config and letting oslo_middleware parse it.

Change-Id: Ibe5dbdc4644ec812f0435f59319666fc336c195a
Partial-Bug: 1713731
diff --git a/lib/nova b/lib/nova
index fa09fd8..887a70d 100644
--- a/lib/nova
+++ b/lib/nova
@@ -555,6 +555,7 @@
 
     if is_service_enabled tls-proxy; then
         iniset $NOVA_CONF DEFAULT glance_protocol https
+        iniset $NOVA_CONF oslo_middleware enable_proxy_headers_parsing True
     fi
 
     if is_service_enabled n-sproxy; then