[geary/wip/fix-gmime-abstract-ctors] Fix GMime custom binding abstract ctors

[Michael Gratton <mjog src gnome org>]

commit f07c84adb33c5f101229bed300e9194d92e2f051
Author: Michael Gratton <mike vee net>
Date:   Wed Jul 17 15:36:09 2019 +1000

    Fix GMime custom binding abstract ctors
    
    Silences compiler warnings produced by current vala head

 bindings/vapi/gmime-2.6.vapi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/bindings/vapi/gmime-2.6.vapi b/bindings/vapi/gmime-2.6.vapi
index ae9458d5..c5d1c0aa 100644
--- a/bindings/vapi/gmime-2.6.vapi
+++ b/bindings/vapi/gmime-2.6.vapi
@@ -676,7 +676,7 @@ namespace GMime {
                public weak GMime.ContentDisposition disposition;
                public weak GMime.HeaderList headers;
                [CCode (cname = "g_mime_object_new", has_construct_function = false)]
-               public Object (GMime.ContentType content_type);
+               protected Object (GMime.ContentType content_type);
                [CCode (cname = "g_mime_object_append_header")]
                public virtual void append_header (string header, string value);
                [CCode (cname = "g_mime_object_encode")]