examples: Change IP address of config files

This helps in providing 3G software packages for the sysmoNITB hardware, which
uses 10.23.24.1 for SGSN and 10.23.24.2 for GGSN.

However, in order to not break the python tests, the osmo-sgsn.cfg example
still uses 127.0.0.1 as local address.

Change the GGSN address to 127.0.0.2, because SGSN and GGSN cannot co-exist on
the same address (the GTP port number is fixed by spec: no IE to communicate a
differing port, so it has to be the standard GTP port for both).

Change-Id: Ie3a25f6771ed6e620cb2b315638c622a9a24e530
diff --git a/doc/examples/osmo-sgsn/osmo-sgsn.cfg b/doc/examples/osmo-sgsn/osmo-sgsn.cfg
index 4955983..3f39397 100644
--- a/doc/examples/osmo-sgsn/osmo-sgsn.cfg
+++ b/doc/examples/osmo-sgsn/osmo-sgsn.cfg
@@ -7,7 +7,7 @@
 !
 sgsn
  gtp local-ip 127.0.0.1
- ggsn 0 remote-ip 127.0.0.1
+ ggsn 0 remote-ip 127.0.0.2
  ggsn 0 gtp-version 1
 !
 ns