Fix compilaion error

I0adf995e1 broke compilation.

Change-Id: I0103c4e348733fc9f07ebe4fb0d749e2136d9a6a

gerrit-server/src/main/java/com/google/gerrit/server/plugins/AutoRegisterModules.java

@@ -65,8 +65,12 @@ class AutoRegisterModules {
     this.env = env;
     this.scanner = scanner;
     this.classLoader = classLoader;
-    this.sshGen = env.hasSshModule() ? env.newSshModuleGenerator() : ModuleGenerator.NOP;
+    this.sshGen = env.hasSshModule()
-    this.httpGen = env.hasHttpModule() ? env.newHttpModuleGenerator() : ModuleGenerator.NOP;
+        ? env.newSshModuleGenerator()
+        : new ModuleGenerator.NOP();
+    this.httpGen = env.hasHttpModule()
+        ? env.newHttpModuleGenerator()
+        : new HttpModuleGenerator.NOP();
   }
 
   AutoRegisterModules discover() throws InvalidPluginException {

gerrit-server/src/main/java/com/google/gerrit/server/plugins/HttpModuleGenerator.java

@@ -14,6 +14,15 @@
 
 package com.google.gerrit.server.plugins;
 
+
 public interface HttpModuleGenerator extends ModuleGenerator {
   void export(String javascript);
+
+  static class NOP extends ModuleGenerator.NOP
+      implements HttpModuleGenerator {
+    @Override
+    public void export(String javascript) {
+      // do nothing
+    }
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/plugins/ModuleGenerator.java

@@ -27,7 +27,7 @@ public interface ModuleGenerator {
 
   Module create() throws InvalidPluginException;
 
-  public static final ModuleGenerator NOP = new ModuleGenerator() {
+  static class NOP implements ModuleGenerator {
 
     @Override
     public void setPluginName(String name) {
@@ -48,5 +48,5 @@ public interface ModuleGenerator {
     public Module create() throws InvalidPluginException {
       return null;
     }
-  };
+  }
 }