Explicitly require wsgi to be enabled in apache2

PROD-32552

Change-Id: I027ffc35c5a09081a8bd565067cdea234e054666
diff --git a/apache/server/site/aodh.yml b/apache/server/site/aodh.yml
index 3b7fc23..abeb151 100644
--- a/apache/server/site/aodh.yml
+++ b/apache/server/site/aodh.yml
@@ -9,6 +9,10 @@
     apache_aodh_api_port: 8042
   apache:
     server:
+      enabled: true
+      default_mpm: event
+      modules:
+        - wsgi
       site:
         aodh:
           enabled: false