Update to vertx-core metrics change

Author: vietj

vertx-sql-client/src/main/java/io/vertx/sqlclient/impl/tracing/QueryReporter.java

@@ -125,7 +125,8 @@ public void before() {
     }
     if (metrics != null) {
       String sql = cmd.sql();
-      metric = metrics.requestBegin(sql, sql);
+      metric = metrics.init();
+      metrics.requestBegin(metric, sql, sql);
       metrics.requestEnd(metric);
     }
   }

vertx-sql-client/src/test/java/io/vertx/tests/sqlclient/tck/MetricsTestBase.java

@@ -300,7 +300,7 @@ private void testMetrics(TestContext ctx, boolean fail, Function<SqlConnection,
     AtomicReference<Object> failureMetric = new AtomicReference<>();
     clientMetrics = new ClientMetrics() {
       @Override
-      public Object requestBegin(String uri, Object request) {
+      public Object init() {
         return metric;
       }
       @Override