Move out gbproxy to its own subdir

Change-Id: I2cc98d3a276d953609bbbbaa9782a0112687791e
diff --git a/debian/copyright b/debian/copyright
index b9bc8e0..695d768 100644
--- a/debian/copyright
+++ b/debian/copyright
@@ -86,12 +86,12 @@
            src/gprs/gprs_gb_parse.c
            src/gprs/gprs_utils.c
            src/gprs/sgsn_ares.c
-           src/gprs/gb_proxy.c
-           src/gprs/gb_proxy_main.c
-           src/gprs/gb_proxy_patch.c
-           src/gprs/gb_proxy_peer.c
-           src/gprs/gb_proxy_tlli.c
-           src/gprs/gb_proxy_vty.c
+           src/gbproxy/gb_proxy.c
+           src/gbproxy/gb_proxy_main.c
+           src/gbproxy/gb_proxy_patch.c
+           src/gbproxy/gb_proxy_peer.c
+           src/gbproxy/gb_proxy_tlli.c
+           src/gbproxy/gb_proxy_vty.c
            src/gprs/gprs_gmm.c
            src/gprs/gprs_llc.c
            src/gprs/gprs_llc_vty.c