gbproxy: Remove patching, TLLI-tracking and SGSN2 support

Those features were introduced a long time ago for one specific use
case at one specific user, and they are not needed anymore.  They
complicate the code base significantly and are hard to maintain with
all the upcoming modifications regarding SGSN pool supoprt.

Change-Id: Id9cc2e1c63486491ac5bb68876088a615075fde6
diff --git a/osmoappdesc.py b/osmoappdesc.py
index e91043f..1fccafd 100644
--- a/osmoappdesc.py
+++ b/osmoappdesc.py
@@ -16,8 +16,7 @@
 
 
 app_configs = {
-    "gbproxy": ["doc/examples/osmo-gbproxy/osmo-gbproxy.cfg",
-             "doc/examples/osmo-gbproxy/osmo-gbproxy-legacy.cfg"],
+    "gbproxy": ["doc/examples/osmo-gbproxy/osmo-gbproxy.cfg"],
     "sgsn": ["doc/examples/osmo-sgsn/osmo-sgsn.cfg"],
     "gtphub": ["doc/examples/osmo-gtphub/osmo-gtphub-1iface.cfg"]
 }