Revert "Remove old fix in ovpn-client"

This reverts commit 24fea8cd.

The client up hook is required when IPv4 is not enabled.

re6st/ovpn-client

 #!/usr/bin/python2 -S
-import os, sys, time
-os.write(int(sys.argv[1]), repr((os.environ['common_name'], time.time(),
-         int(os.environ['tls_serial_0']), os.environ['OPENVPN_external_ip'])))
+import os, sys
+
+script_type = os.environ['script_type']
+if script_type == 'up':
+    # OpenVPN only brings the interface up when it's called with --ifconfig
+    # i.e. when IPv4 mode is enabled in re6st.
+    # OpenVPN unsets PATH before calling hooks
+    # which is equivalent to set /bin:/usr/bin
+    os.environ['PATH'] = '/bin:/sbin:/usr/bin:/usr/sbin'
+    os.execlp('ip', 'ip', 'link', 'set', os.environ['dev'], 'up',
+              'mtu', os.environ['tun_mtu'])
+
+if script_type == 'route-up':
+    import time
+    os.write(int(sys.argv[1]), repr((os.environ['common_name'], time.time(),
+        int(os.environ['tls_serial_0']), os.environ['OPENVPN_external_ip'])))

re6st/plib.py

@@ -13,6 +13,7 @@ def openvpn(iface, encrypt, *args, **kw):
         '--persist-tun',
         '--persist-key',
         '--script-security', '2',
+        '--up', ovpn_client,
         #'--user', 'nobody', '--group', 'nogroup',
         ] + list(args)
     if ovpn_log: