cosmetic: drop unused struct mgcp_ctx shadow

Change-Id: If9c705e9fe6dba9225f7dec045e790af7a875ee8
diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h
index 4d27a2e..c4315c0 100644
--- a/include/osmocom/bsc/gsm_data.h
+++ b/include/osmocom/bsc/gsm_data.h
@@ -38,7 +38,6 @@
 
 struct mgcp_client_conf;
 struct mgcp_client;
-struct mgcp_ctx;
 struct gsm0808_cell_id;
 struct mgw_endpoint;