[evolution-data-server] Hide sendmail in Flatpak

[Milan Crha <mcrha src gnome org>]

commit 3d5a77e42c38e3f601e4e7c0377dffb6524b4b35
Author: Milan Crha <mcrha redhat com>
Date:   Fri Feb 15 08:52:35 2019 +0100

    Hide sendmail in Flatpak
    
    It cannot access the host sendmail anyway, neither any custom binary
    from the host.

 src/camel/providers/sendmail/camel-sendmail-provider.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/src/camel/providers/sendmail/camel-sendmail-provider.c 
b/src/camel/providers/sendmail/camel-sendmail-provider.c
index 252208baa..6450ad2c5 100644
--- a/src/camel/providers/sendmail/camel-sendmail-provider.c
+++ b/src/camel/providers/sendmail/camel-sendmail-provider.c
@@ -56,6 +56,9 @@ camel_provider_module_init (void)
        sendmail_provider.url_equal = (GEqualFunc) camel_url_equal;
        sendmail_provider.translation_domain = GETTEXT_PACKAGE;
 
-       camel_provider_register (&sendmail_provider);
+       /* Hide sendmail in Flatpak. It cannot access the host sendmail
+          anyway, neither any custom binary from the host. */
+       if (!g_file_test ("/.flatpak-info", G_FILE_TEST_EXISTS))
+               camel_provider_register (&sendmail_provider);
 }