Fix the update_url_parms method to handle parsing multiple url params

Used Rack::Utils.parse_query to parse the url parameters specified as
a string.

https://bugzilla.redhat.com/show_bug.cgi?id=1141974
Merge pull request #614 from AparnaKarve/multiple_url_parameters_specified_as_string

Fix the update_url_parms method to handle parsing multiple url params