Use moved FactoryModule

The factory module moved upstream.

Change-Id: If4c88640360a694f67ffd263d51c8a0dfd8a82f1
diff --git a/src/main/java/com/googlesource/gerrit/plugins/xdocs/Module.java b/src/main/java/com/googlesource/gerrit/plugins/xdocs/Module.java
index 70506c5..b90db61 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/xdocs/Module.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/xdocs/Module.java
@@ -18,6 +18,7 @@
 import com.google.gerrit.extensions.annotations.Exports;
 import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.client.GerritTopMenu;
+import com.google.gerrit.extensions.config.FactoryModule;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.webui.BranchWebLink;
@@ -25,7 +26,6 @@
 import com.google.gerrit.extensions.webui.FileWebLink;
 import com.google.gerrit.extensions.webui.ProjectWebLink;
 import com.google.gerrit.extensions.webui.TopMenu;
-import com.google.gerrit.server.config.FactoryModule;
 import com.google.inject.Inject;
 
 import com.googlesource.gerrit.plugins.xdocs.formatter.AsciidoctorFormatter;