Fixed memory-leak in utf8::to_string().
Fixed memory-leak in utf8::to_string().

bgarrels/zorba,28msec/zorba,28msec/zorba,bgarrels/zorba,cezarfx/zorba,cezarfx/zorba,28msec/zorba,28msec/zorba,28msec/zorba,28msec/zorba,28msec/zorba,cezarfx/zorba,bgarrels/zorba,cezarfx/zorba,28msec/zorba,bgarrels/zorba,cezarfx/zorba,bgarrels/zorba,bgarrels/zorba,bgarrels/zorba,cezarfx/zorba,28msec/zorba,cezarfx/zorba,cezarfx/zorba,cezarfx/zorba,bgarrels/zorba,cezarfx/zorba