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