crypto: Avoid explicit handling of GMimeCryptoContext in gmime 3

gmime 3.0 knows how to select the correct GMimeCryptoContext
automatically, so a bunch of the code in notmuch can be dropped in
that case.

The #ifdef removal of the crypto stuff is better than #define aliasing
in gmime-extra.h for this stuff.  When built against gmime 3.0:

    * it reduces compiled code, and
    * it avoids initializing unused gpgme contexts

(based on a patch from dkg)

1 files changed, 7 insertions, 1 deletions

diff --git a/crypto.c b/crypto.c
index 3e8ce7ca..cc45b885 100644
--- a/crypto.c
+++ b/crypto.c
@@ -19,7 +19,7 @@
  */
 
 #include "notmuch-client.h"
-
+#if (GMIME_MAJOR_VERSION < 3)
 /* Create a GPG context (GMime 2.6) */
 static notmuch_crypto_context_t *
 create_gpg_context (notmuch_crypto_t *crypto)
@@ -132,3 +132,9 @@ notmuch_crypto_cleanup (notmuch_crypto_t *crypto)
 
     return 0;
 }
+#else
+int notmuch_crypto_cleanup (unused(notmuch_crypto_t *crypto))
+{
+    return 0;
+}
+#endif