add TODO

Signed-off-by: Sergei Malafeev <sergeymalafeev@gmail.com>

opentracing-redis-spring/src/main/java/io/opentracing/contrib/redis/spring/connection/TracingRedisConnectionFactory.java

@@ -77,6 +77,7 @@ public ReactiveRedisConnection getReactiveConnection() {
       return new TracingReactiveRedisConnection((ReactiveRedisConnection) delegate,
           withActiveSpanOnly, tracer);
     }
+    // TODO: shouldn't we throw an exception?
     return null;
   }
 
@@ -85,6 +86,7 @@ public ReactiveRedisClusterConnection getReactiveClusterConnection() {
     if (delegate instanceof ReactiveRedisConnectionFactory) {
       return ((ReactiveRedisConnectionFactory) delegate).getReactiveClusterConnection();
     }
+    // TODO: shouldn't we throw an exception?
     return null;
   }
 }