minor: cleanup comboparse and http2

comboparse.py

@@ -2,7 +2,10 @@
 # -*- coding: utf-8 -*-
 """Combined config file and argument parser."""
 
-from ConfigParser import SafeConfigParser, NoOptionError
+try:
+    from ConfigParser import SafeConfigParser, NoOptionError
+except ImportError:
+    from configparser import SafeConfigParser, NoOptionError
 from argparse import ArgumentParser
 import sys
 

http2.py

@@ -42,7 +42,7 @@ def _parse_url(url):
 		url = url[1:]
 		port = 0
 	else:
-		raise
+		raise ValueError("invalid URL scheme: %s" % url[:50])
 
 	if not '/' in url: url = url + '/'