Remove more references to GAE (#2894)

These are old/pointless now that we've migrated to GKE. Note that this
doesn't update anything in the docs/ folder, as that's a much larger
project that should be done on its own.

networking/src/main/java/google/registry/networking/handler/SslServerInitializer.java

@@ -54,8 +54,8 @@ import javax.net.ssl.SSLSession;
  * <p>The ssl handler added can require client authentication, but it uses an {@link
  * InsecureTrustManagerFactory}, which accepts any ssl certificate presented by the client, as long
  * as the client uses the corresponding private key to establish SSL handshake. The client
- * certificate hash will be passed along to GAE as an HTTP header for verification (not handled by
- * this handler).
+ * certificate hash will be passed along to the service as an HTTP header for verification (not
+ * handled by this handler).
  */
 @Sharable
 public class SslServerInitializer<C extends Channel> extends ChannelInitializer<C> {