Correctly manage NUL characters in UTF8 normalization
Correctly manage NUL characters in UTF8 normalization

If the input striing isn't UTF-8 encoded, the normalization returns an
empty string.

thedebian/sdk,Novo1987/sdk,18671178307/sdk,meganz/sdk,SuperStarPL/sdk,BlackFired/sdk,BiuroCo/mega,thedebian/sdk,18671178307/sdk,Alexx99/sdk,Acidburn0zzz/sdk,Novo1987/sdk,18671178307/sdk,Acidburn0zzz/sdk,BiuroCo/mega,18671178307/sdk,18671178307/sdk,jedisct1/sdk,sergiohs84/sdk,javiserrano/sdk,Sisky/sdk,javiserrano/sdk,SuperStarPL/sdk,BiuroCo/mega,Acidburn0zzz/sdk,PatrickJBaird/sdk,PatrickJBaird/sdk,Alexx99/sdk,Acidburn0zzz/sdk,Acidburn0zzz/sdk,Acidburn0zzz/sdk,javiserrano/sdk,Sisky/sdk,thedebian/sdk,sergiohs84/sdk,PatrickJBaird/sdk,wizzard/sdk,jedisct1/sdk,18671178307/sdk,wizzard/sdk,PatrickJBaird/sdk,thedebian/sdk,BlackFired/sdk,Alexx99/sdk,Alexx99/sdk,sergiohs84/sdk,meganz/sdk,18671178307/sdk,wizzard/sdk,sergiohs84/sdk,Acidburn0zzz/sdk,BlackFired/sdk,meganz/sdk,Alexx99/sdk,BlackFired/sdk,thedebian/sdk,jedisct1/sdk,meganz/sdk,Novo1987/sdk,18671178307/sdk,javiserrano/sdk,Novo1987/sdk,SuperStarPL/sdk,SuperStarPL/sdk,Sisky/sdk,Novo1987/sdk,jedisct1/sdk,PatrickJBaird/sdk,Novo1987/sdk,Sisky/sdk,meganz/sdk,Novo1987/sdk,BlackFired/sdk,thedebian/sdk,wizzard/sdk,javiserrano/sdk,BiuroCo/mega,jedisct1/sdk,Novo1987/sdk,Acidburn0zzz/sdk,Sisky/sdk,javiserrano/sdk,BlackFired/sdk,Sisky/sdk,meganz/sdk,jedisct1/sdk,sergiohs84/sdk,PatrickJBaird/sdk,jedisct1/sdk,sergiohs84/sdk,jedisct1/sdk,SuperStarPL/sdk,meganz/sdk,sergiohs84/sdk,SuperStarPL/sdk,BiuroCo/mega,Alexx99/sdk,BiuroCo/mega,sergiohs84/sdk