Dev mode: several Vert.x worker threads detecting the change
Still with a very simple getting-started application.

I start in dev mode. I don't load anything. I go to the `src/main/java/org/acme/quickstart/GreetingResource.java` resource and remove a semi-colon to have a compilation error.

When I load the `http://localhost:8080/hello` page, I end up with several Vert.x worker threads signaling the change:
```
2019-09-04 11:13:58,811 INFO  [io.qua.dev] (vert.x-worker-thread-0) Changed source files detected, recompiling [/tmp/getting-started/src/main/java/org/acme/quickstart/GreetingResource.java]
2019-09-04 11:13:58,818 INFO  [io.qua.dev] (vert.x-worker-thread-1) Changed source files detected, recompiling [/tmp/getting-started/src/main/java/org/acme/quickstart/GreetingResource.java]
2019-09-04 11:14:04,274 INFO  [io.qua.dev] (vert.x-worker-thread-2) Changed source files detected, recompiling [/tmp/getting-started/src/main/java/org/acme/quickstart/GreetingResource.java]
2019-09-04 11:14:25,273 INFO  [io.qua.dev] (vert.x-worker-thread-3) Changed source files detected, recompiling [/tmp/getting-started/src/main/java/org/acme/quickstart/GreetingResource.java]
```

It's variable, sometimes I have 1, sometimes 2, and sometimes like in this case 4.
diff --git a/extensions/vertx-web/deployment/src/main/java/io/quarkus/vertx/web/deployment/devmode/VertxHotReplacementSetup.java b/extensions/vertx-web/deployment/src/main/java/io/quarkus/vertx/web/deployment/devmode/VertxHotReplacementSetup.java
index 9f49c32b810..416f5cd166a 100644
--- a/extensions/vertx-web/deployment/src/main/java/io/quarkus/vertx/web/deployment/devmode/VertxHotReplacementSetup.java
+++ b/extensions/vertx-web/deployment/src/main/java/io/quarkus/vertx/web/deployment/devmode/VertxHotReplacementSetup.java
@@ -47,13 +47,13 @@ public void handle(Promise<Boolean> event) {
                 boolean restart = false;
                 synchronized (this) {
                     if (nextUpdate < System.currentTimeMillis() || hotReplacementContext.isTest()) {
+                        nextUpdate = System.currentTimeMillis() + HOT_REPLACEMENT_INTERVAL;
                         try {
                             restart = hotReplacementContext.doScan(true);
                         } catch (Exception e) {
                             event.fail(new IllegalStateException("Unable to perform hot replacement scanning", e));
                             return;
                         }
-                        nextUpdate = System.currentTimeMillis() + HOT_REPLACEMENT_INTERVAL;
                     }
                 }
                 if (hotReplacementContext.getDeploymentProblem() != null) {
['extensions/vertx-web/deployment/src/main/java/io/quarkus/vertx/web/deployment/devmode/VertxHotReplacementSetup.java']