osmo-ggsn.cfg: Ensure well-formed config file example

Change-Id: Ic7fd91745e7442eda741d46748c0a4a02dedef80
diff --git a/doc/examples/osmo-ggsn.cfg b/doc/examples/osmo-ggsn.cfg
index 8317684..4000636 100644
--- a/doc/examples/osmo-ggsn.cfg
+++ b/doc/examples/osmo-ggsn.cfg
@@ -3,32 +3,32 @@
 !!
 !
 log stderr
-  logging filter all 1
-  logging color 1
-  logging print category 0
-  logging timestamp 0
-  logging level ip info
-  logging level tun info
-  logging level ggsn info
-  logging level sgsn notice
-  logging level icmp6 notice
-  logging level lglobal notice
-  logging level llapd notice
-  logging level linp notice
-  logging level lmux notice
-  logging level lmi notice
-  logging level lmib notice
-  logging level lsms notice
-  logging level lctrl notice
-  logging level lgtp info
-  logging level lstats notice
-  logging level lgsup notice
-  logging level loap notice
-  logging level lss7 notice
-  logging level lsccp notice
-  logging level lsua notice
-  logging level lm3ua notice
-  logging level lmgcp notice
+ logging filter all 1
+ logging color 1
+ logging print category 0
+ logging timestamp 0
+ logging level ip info
+ logging level tun info
+ logging level ggsn info
+ logging level sgsn notice
+ logging level icmp6 notice
+ logging level lglobal notice
+ logging level llapd notice
+ logging level linp notice
+ logging level lmux notice
+ logging level lmi notice
+ logging level lmib notice
+ logging level lsms notice
+ logging level lctrl notice
+ logging level lgtp info
+ logging level lstats notice
+ logging level lgsup notice
+ logging level loap notice
+ logging level lss7 notice
+ logging level lsccp notice
+ logging level lsua notice
+ logging level lm3ua notice
+ logging level lmgcp notice
 !
 stats interval 5
 !