Relax assertion on open file descriptors

In the stress test. It seems to require a bit more open file
descriptors with async API. Also added printing of FD count.

Author: lutovich

driver/src/test/java/org/neo4j/driver/v1/stress/AbstractStressTestBase.java

@@ -305,9 +305,13 @@ private void verifyResults( C context, ResourcesInfo resourcesInfo )
 
     private void assertNoFileDescriptorLeak( long previousOpenFileDescriptors )
     {
-        // number of open file descriptors should not go up for more than 20%
-        long maxOpenFileDescriptors = (long) (previousOpenFileDescriptors * 1.2);
+        System.out.println( "Initially open file descriptors: " + previousOpenFileDescriptors );
+
+        // number of open file descriptors should not go up for more than 30%
+        long maxOpenFileDescriptors = (long) (previousOpenFileDescriptors * 1.3);
         long currentOpenFileDescriptorCount = getOpenFileDescriptorCount();
+        System.out.println( "Currently open file descriptors: " + currentOpenFileDescriptorCount );
+
         assertThat( "Unexpectedly high number of open file descriptors",
                 currentOpenFileDescriptorCount, lessThanOrEqualTo( maxOpenFileDescriptors ) );
     }