[glom/glom-1-28] Bakery::Document::get_read_only(): Add a missing !.

[Murray Cumming <murrayc src gnome org>]

commit 0b44d77a56f3df98576f053ca6b08eefc609acba
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Jul 6 20:09:51 2015 +0200

    Bakery::Document::get_read_only(): Add a missing !.
    
    So this works as expected now that the code reaches this far
    due to commit 16d5d1dfa185e9c46f965ae0cb7af22584fc6af9

 glom/libglom/document/bakery/document.cc |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glom/libglom/document/bakery/document.cc b/glom/libglom/document/bakery/document.cc
index 5fbbec0..e2bc172 100644
--- a/glom/libglom/document/bakery/document.cc
+++ b/glom/libglom/document/bakery/document.cc
@@ -463,7 +463,7 @@ bool Document::get_read_only() const
       if(!info)
         return false;
 
-      const bool read_only = info->get_attribute_boolean(G_FILE_ATTRIBUTE_ACCESS_CAN_WRITE);
+      const bool read_only = !info->get_attribute_boolean(G_FILE_ATTRIBUTE_ACCESS_CAN_WRITE);
       return read_only;
     }
   }