test: fix pooling tests

Author: Alex-pvl

tarantool-pooling/src/test/java/io/tarantool/pool/integration/BasePoolTest.java

@@ -162,6 +162,9 @@ protected List<IProtoClient> getConnects(IProtoClientPool pool, String tag, int
       futures.add(pool.get(tag, i));
     }
     CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();
+    for (CompletableFuture<IProtoClient> future : futures) {
+      clients.add(future.join());
+    }
     return clients;
   }