Move out sgsn to its own subdir

Change-Id: I16fccc0eadf588599b9e5578d0f4dbaf9df81737
diff --git a/osmoappdesc.py b/osmoappdesc.py
index 9c3fd5d..08166a9 100644
--- a/osmoappdesc.py
+++ b/osmoappdesc.py
@@ -24,11 +24,11 @@
 
 
 apps = [(4246, "src/gbproxy/osmo-gbproxy", "OsmoGbProxy", "gbproxy"),
-        (4245, "src/gprs/osmo-sgsn", "OsmoSGSN", "sgsn"),
+        (4245, "src/sgsn/osmo-sgsn", "OsmoSGSN", "sgsn"),
         (4253, "src/gtphub/osmo-gtphub", "OsmoGTPhub", "gtphub")
         ]
 
-vty_command = ["./src/gprs/osmo-sgsn", "-c",
+vty_command = ["./src/sgsn/osmo-sgsn", "-c",
                "doc/examples/osmo-sgsn/osmo-sgsn.cfg"]
 
 vty_app = apps[1]