Fix quickstart inject

Author: romain-grecourt

examples/quickstarts/helidon-quickstart-inject/src/main/java/io/helidon/examples/quickstart/inject/GreetService.java

@@ -20,7 +20,7 @@
 import java.util.concurrent.atomic.AtomicReference;
 
 import io.helidon.common.Default;
-import io.helidon.common.config.Configuration;
+import io.helidon.config.Configuration;
 import io.helidon.http.Status;
 import io.helidon.service.registry.Service;
 import io.helidon.webserver.http.HttpRules;