Fix for WRO: some locations give no result

The cause: a UnicodeDecodeerror: `'ascii' codec can't encode character u'\xb3' in position 8: ordinal not in range(128)`

The locations where there are no results are those for "Debiet m³/s". Note the nice non-7bit-ascii "m³".

I've fixed the part of our code where this caused an error.