It's not a big deal. If it is buzzing, then you should try to find out the moving part of the siyahi by hitting. Most of the times, it is difficult to find out but if you can find out, then either you remove that moving portion or put some gum (very little) only on that portion. Let it dry. But remember one thing, putting something sticky such as gum to other part of the siyahi may cut it's resonance or block the sound of your tabla. So, don't put the gum on other part of the siyahi. Otherwise you may spoil the skin.