[vte] build: Add -Wvla

[Egmont Koblinger <egmontkob src gnome org>]

commit 5a01bf95904148a06baf7f908f7321ff3fc7d1a8
Author: Egmont Koblinger <egmont gmail com>
Date:   Thu Jan 3 13:51:27 2019 +0100

    build: Add -Wvla

 configure.ac | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/configure.ac b/configure.ac
index 57d9c3ad..1218e0db 100644
--- a/configure.ac
+++ b/configure.ac
@@ -170,6 +170,7 @@ m4_define([compiler_flags_common],[ dnl
   -Wundef dnl
   -Wuninitialized dnl
   -Wunsafe-loop-optimizations dnl
+  -Wvla dnl
   -Wwrite-strings dnl
   -fno-common dnl
   -fdiagnostics-show-option dnl