MINOR: quic: Avoid warning about NULL pointer dereferences

This is the same fixe as for this commit:
    "BUILD: tree-wide: avoid warnings caused by redundant checks of obj_types"
Should fix CID 1469649 for GH #1546
diff --git a/src/proto_quic.c b/src/proto_quic.c
index 5296721..e3ea509 100644
--- a/src/proto_quic.c
+++ b/src/proto_quic.c
@@ -263,11 +263,11 @@
 
 	switch (obj_type(conn->target)) {
 	case OBJ_TYPE_PROXY:
-		be = objt_proxy(conn->target);
+		be = __objt_proxy(conn->target);
 		srv = NULL;
 		break;
 	case OBJ_TYPE_SERVER:
-		srv = objt_server(conn->target);
+		srv = __objt_server(conn->target);
 		be = srv->proxy;
 		break;
 	default: