[vte] build: Don't warn on volatile

[Christian Persch <chpe src gnome org>]

commit 99a06254d5137065122124ae74ca9fcb5c2ef56c
Author: Christian Persch <chpe src gnome org>
Date:   Wed Feb 24 20:22:10 2021 +0100

    build: Don't warn on volatile
    
    ... which comes in from gobject headers.

 meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/meson.build b/meson.build
index 866d87f2..c200f361 100644
--- a/meson.build
+++ b/meson.build
@@ -324,6 +324,7 @@ compiler_flags_common = [
   '-Wno-packed',
   '-Wno-switch-enum',
   '-Wno-unused-parameter',
+  '-Wno-volatile',
   '-Wshadow',
   '-Wshift-negative-value',
   '-Wsign-compare',