[BUG] cookie capture is declared in the frontend but checked on the backend

Cookie capture would only work by pure luck on the request but did
never work on responses since only the backend was checked. The fix
consists in always checking frontend for cookie captures.
(cherry picked from commit a83c5ba9315a7c47cda2698280b7e49a9d3eb374)
diff --git a/src/proto_http.c b/src/proto_http.c
index f931da4..71013d4 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -2142,7 +2142,7 @@
 	 * the fields will stay coherent and the URI will not move.
 	 * This should only be performed in the backend.
 	 */
-	if ((s->be->cookie_name || s->be->appsession_name || s->be->capture_name)
+	if ((s->be->cookie_name || s->be->appsession_name || s->fe->capture_name)
 	    && !(txn->flags & (TX_CLDENY|TX_CLTARPIT)))
 		manage_client_side_cookies(s, req);
 
@@ -2845,7 +2845,7 @@
 		/*
 		 * 4: check for server cookie.
 		 */
-		if (t->be->cookie_name || t->be->appsession_name || t->be->capture_name
+		if (t->be->cookie_name || t->be->appsession_name || t->fe->capture_name
 		    || (t->be->options & PR_O_CHK_CACHE))
 			manage_server_side_cookies(t, rep);
 
@@ -3921,10 +3921,12 @@
 		txn->flags |= TX_SCK_ANY;
 
 
-		/* maybe we only wanted to see if there was a set-cookie */
+		/* maybe we only wanted to see if there was a set-cookie. Note that
+		 * the cookie capture is declared in the fronend.
+		 */
 		if (t->be->cookie_name == NULL &&
 		    t->be->appsession_name == NULL &&
-		    t->be->capture_name == NULL)
+		    t->fe->capture_name == NULL)
 			return;
 
 		p1 = cur_ptr + val; /* first non-space char after 'Set-Cookie:' */
@@ -3956,18 +3958,18 @@
 			 */
 
 			/* first, let's see if we want to capture it */
-			if (t->be->capture_name != NULL &&
+			if (t->fe->capture_name != NULL &&
 			    txn->srv_cookie == NULL &&
-			    (p4 - p1 >= t->be->capture_namelen) &&
-			    memcmp(p1, t->be->capture_name, t->be->capture_namelen) == 0) {
+			    (p4 - p1 >= t->fe->capture_namelen) &&
+			    memcmp(p1, t->fe->capture_name, t->fe->capture_namelen) == 0) {
 				int log_len = p4 - p1;
 
 				if ((txn->srv_cookie = pool_alloc2(pool2_capture)) == NULL) {
 					Alert("HTTP logging : out of memory.\n");
 				}
 
-				if (log_len > t->be->capture_len)
-					log_len = t->be->capture_len;
+				if (log_len > t->fe->capture_len)
+					log_len = t->fe->capture_len;
 				memcpy(txn->srv_cookie, p1, log_len);
 				txn->srv_cookie[log_len] = 0;
 			}