Update wikipedia.py

I modified that line to avoid a error of encoding when asking for a section which has special characters. The error was produced in the format() function, so I removed it and concatenate the Strings. If I'm not wrong it does the same effect.
Update wikipedia.py

Corrected thanks to @goldsmith advice.
Merge pull request #31 from javierprovecho/patch-1

Fix section getting for sections with unicode titles