[PATCH] fix build failure with glib 2.67

[David Bremner <david@tethera.net>]

Based on a patch from Michael J Gruber [1].  As of glib 2.67 (more
specifically [2]), including "gmime-extra.h" inside an extern "C"
block causes build failures, because glib is using C++ features.

Observing that "gmime-extra.h" is no longer needed in
notmuch-private.h, which can simply delete that include, but
we have to correspondingly move the includes which might include
it (in particular crypto.h) out of the extern "C" block also.

This seems less fragile than only moving gmime-extra, and relying on
preprocessor sentinels to keep the deeper includes from happening.

Move to the include to the outside of the extern block.

[1]: id:aee618a3d41f7889a7449aa16893e992325a909a.1613055071.git.git@grubix.eu
[2]: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1715
---

 I neglected to change the author when amending. No fair blaming
 Michael for my potential mistakes
 
 lib/notmuch-private.h | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 57ec7f72..41aff342 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -31,6 +31,12 @@
 
 #include "notmuch.h"
 
+#include "xutil.h"
+#include "error_util.h"
+#include "string-util.h"
+#include "crypto.h"
+#include "repair.h"
+
 NOTMUCH_BEGIN_DECLS
 
 #include <stdlib.h>
@@ -47,14 +53,6 @@ NOTMUCH_BEGIN_DECLS
 
 #include <talloc.h>
 
-#include "gmime-extra.h"
-
-#include "xutil.h"
-#include "error_util.h"
-#include "string-util.h"
-#include "crypto.h"
-#include "repair.h"
-
 #ifdef DEBUG
 # define DEBUG_DATABASE_SANITY 1
 # define DEBUG_THREADING 1
-- 
2.30.0