Firstly I would like to note that my qgis-webclient and the wsgi searching are all working correctly as they should. After creating afew datatables for test purposes the url: http://localhost:1234/wsgi/search.wsgi?query=&searchtables=&query=11&cb=stcCallback1002 returned the correct values. Now my problem is that the encoding used in the wsgi script is using an python file somedisk\somepath\OSGeo4W\apps\Python27\Lib\json\encoding.py. With this file the text returned is encoded in UTF-8.
Now my question is how can I change this encoding to something different, in my case WIN1250 (ISO/IEC 8859-2).