fixed 23 bug

src/detect-http-cookie.c

@@ -75,6 +75,10 @@ int DetectHttpCookieMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx,
         return 0;
     }
 
+    if (htp_state->connp->conn == NULL) {
+        SCLogDebug("HTTP connection structure is NULL");
+        return 0;
+    }
     int ret = 0;
     SCMutexLock(&f->m);
     htp_tx_t *tx = list_get(htp_state->connp->conn->transactions, 0);