Increase number of concurrent requests in NettyHttpRequestSizeLimitIT

For some seeds the number of concurrent requests previously defined
in NettyHttpRequestSizeLimitIT was too low to trigger the intended
breaker limit.

With this commit we increase the number of concurrent requests that
are sent to the test cluster thus triggering the limit.

core/src/test/java/org/elasticsearch/http/netty/NettyHttpRequestSizeLimitIT.java

@@ -68,17 +68,10 @@ public void testLimitsInFlightRequests() throws Exception {
         }
 
         @SuppressWarnings("unchecked")
-        Tuple<String, CharSequence>[] requests = new Tuple[] {
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest),
-            Tuple.tuple("/index/type/_bulk", bulkRequest)
-        };
+        Tuple<String, CharSequence>[] requests = new Tuple[150];
+        for (int i = 0; i < requests.length; i++) {
+            requests[i] = Tuple.tuple("/index/type/_bulk", bulkRequest);
+        }
 
         HttpServerTransport httpServerTransport = internalCluster().getInstance(HttpServerTransport.class);
         InetSocketTransportAddress inetSocketTransportAddress = (InetSocketTransportAddress) randomFrom(httpServerTransport.boundAddress