[geary: 2/4] Use backup extension when calling sed -i

[Michael Gratton <mjog src gnome org>]

commit f09e5d7c6d696b184cefa52871fb9fac381e2447
Author: Greg V <greg@unrelenting.technology>
Date:   Wed Jan 9 12:30:49 2019 +0300

    Use backup extension when calling sed -i
    
    BSD sed doesn't support -i without the backup extension.

 src/engine/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/engine/meson.build b/src/engine/meson.build
index 796e18d1..de98f4f7 100644
--- a/src/engine/meson.build
+++ b/src/engine/meson.build
@@ -372,7 +372,7 @@ geary_engine_internal_header_fixup = custom_target(
   ],
   command: [
     find_program('sed'),
-    '-i',
+    '-ibak',
     's/geary-engine.h/geary-engine-internal.h/g',
     '@OUTDIR@/geary-engine-internal.vapi',
   ],