Merge pull request #438 from Cqoicebordel/error_page_format

Don't throw away the request if pageno is wrong

searx/search.py

         # set pagenumber
         pageno_param = self.request_data.get('pageno', '1')
         if not pageno_param.isdigit() or int(pageno_param) < 1:
-            raise Exception('wrong pagenumber')
+            pageno_param = 1
 
         self.pageno = int(pageno_param)