[geary] Remove unused source file

[Michael Gratton <mjog src gnome org>]

commit 72ba5e688a6b1939937827de9f4b23c7ffbba2a1
Author: Michael Gratton <mike vee net>
Date:   Fri Feb 15 14:03:09 2019 +1100

    Remove unused source file

 po/POTFILES.in                                     |  1 -
 .../imap-engine/imap-engine-batch-operations.vala  | 79 ----------------------
 src/engine/meson.build                             |  1 -
 3 files changed, 81 deletions(-)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index e8d19a13..52ce78a1 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -233,7 +233,6 @@ src/engine/imap-engine/gmail/imap-engine-gmail-spam-trash-folder.vala
 src/engine/imap-engine/imap-engine-account-operation.vala
 src/engine/imap-engine/imap-engine-account-processor.vala
 src/engine/imap-engine/imap-engine-account-synchronizer.vala
-src/engine/imap-engine/imap-engine-batch-operations.vala
 src/engine/imap-engine/imap-engine-contact-store.vala
 src/engine/imap-engine/imap-engine-email-prefetcher.vala
 src/engine/imap-engine/imap-engine-generic-account.vala
diff --git a/src/engine/meson.build b/src/engine/meson.build
index a33d58b0..f9fb1626 100644
--- a/src/engine/meson.build
+++ b/src/engine/meson.build
@@ -188,7 +188,6 @@ geary_engine_vala_sources = files(
   'imap-engine/imap-engine-account-operation.vala',
   'imap-engine/imap-engine-account-processor.vala',
   'imap-engine/imap-engine-account-synchronizer.vala',
-  'imap-engine/imap-engine-batch-operations.vala',
   'imap-engine/imap-engine-contact-store.vala',
   'imap-engine/imap-engine-email-prefetcher.vala',
   'imap-engine/imap-engine-generic-account.vala',