W3C issues in Prev. Next Jumpers [Buttons]

[sanonline]

This is related to #280

@afc163 Thank you very much for fixing this so quickly. I have checked the latest version 2.4.0 and now it has generated 2 W3C issues for two buttons.

Please have a look. Hope you can fix them soon.

[sanonline]

@afc163 I have upgraded the rc-pagination to v2.4.1, but still I couldn't see that the jumpers get "aria-label" instead of "label". What could be the reason?