Fix goucima parsing from the source, broken by Python3 port

This regular expression:

    patt_s = re.compile(r' *([^\s]+) *\t *([\x00-\xff]{3}) *\t *[^\s]+ *$')

which tries to match single Chinese characters as a sequence of 3
bytes does not match anymore after the Python3 port because Python
strings are always unicode now and each Chinese character is thus a
single character in a string.