[BugFix][Bug-90676][GSW][data]设置apn参数时填写usr和pwd参数会导致api卡住

Change-Id: I3e2dcf1a4b7b0aa4c9b9a4385c031b948aec93b0
diff --git a/mbtk/mbtk_rild/src/mbtk_info_server.c b/mbtk/mbtk_rild/src/mbtk_info_server.c
index 8862a33..6c1ac75 100755
--- a/mbtk/mbtk_rild/src/mbtk_info_server.c
+++ b/mbtk/mbtk_rild/src/mbtk_info_server.c
@@ -3702,7 +3702,7 @@
 
     if(!str_empty(apn->user) || !str_empty(apn->pass)) {
         at_response_free(response);
-
+        response = NULL;
         memset(cmd,0,400);
         int cmd_auth=0;
         if(strstr((char*)apn->auth,"NONE"))