Extend ServletModule instead of HttpPluginModule

As described in I3b89150d1.

Change-Id: Ic91ce95719c6bccc73cc29a2139a2274f20d1939

src/main/java/com/ericsson/gerrit/plugins/eventslog/HttpModule.java

diff --git a/src/main/java/com/ericsson/gerrit/plugins/eventslog/HttpModule.java b/src/main/java/com/ericsson/gerrit/plugins/eventslog/HttpModule.java
index c1db514..b35d1dc 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/eventslog/HttpModule.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/eventslog/HttpModule.java
@@ -14,9 +14,9 @@
 
 package com.ericsson.gerrit.plugins.eventslog;
 
-import com.google.gerrit.httpd.plugins.HttpPluginModule;
+import com.google.inject.servlet.ServletModule;
 
-class HttpModule extends HttpPluginModule {
+class HttpModule extends ServletModule {
   @Override
   protected void configureServlets() {
     serve("/events/").with(EventsRestApiServlet.class);