[vte] lib: Make debug assertion conditional on VTE_DEBUG

[Christian Persch <chpe src gnome org>]

commit a7cf5d57115ed3b6ffd62b375c12a6c3eae5ee73
Author: Christian Persch <chpe src gnome org>
Date:   Mon Sep 3 16:10:51 2018 +0200

    lib: Make debug assertion conditional on VTE_DEBUG

 src/vte.cc | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/vte.cc b/src/vte.cc
index a130a044..069ff7dc 100644
--- a/src/vte.cc
+++ b/src/vte.cc
@@ -3614,8 +3614,10 @@ Terminal::process_incoming()
                                         break;
                                 }
 
+#ifdef VTE_DEBUG
                                 if (rv != VTE_SEQ_NONE)
                                         g_assert((bool)seq);
+#endif
 
                                 _VTE_DEBUG_IF(VTE_DEBUG_PARSER) {
                                         if (rv != VTE_SEQ_NONE) {