ascii values without \x00 ending

[EasyIsrael]

in some images there are ascii values without terminating null character ( \x00 ). this is a fix for that case. It reduces all characters after a null character in an ascii text

the Github- project exifread solves this problem the same way. Have a look at https://github.com/ianare/exif-py/blob/develop/exifread/classes.py in method _process_field2 on line 193.