Fix freebusy for multidomain environments

When returning contacts we have to supply also the domain field.
Because in a multidomain environment UIDField is unique only in
the domain so an user must be identified as uid@domain.

So when creating http requests from client side, we have to use
uid@domain instead of only uid so the SOGoUser created on server
side when parsing the requests is created properly.

SoObjects/Contacts/SOGoContactSourceFolder.m

@@ -48,6 +48,7 @@
 #import <SOGo/SOGoPermissions.h>
 #import <SOGo/SOGoSource.h>
 #import <SOGo/SOGoUserSettings.h>
+#import <SOGo/SOGoSystemDefaults.h>
 #import <SOGo/WORequest+SOGo.h>
 #import <SOGo/WOResponse+SOGo.h>
 
@@ -236,6 +237,13 @@
     data = @"";
   [newRecord setObject: data forKey: @"c_cn"];
 
+  if ([[SOGoSystemDefaults sharedSystemDefaults] enableDomainBasedUID])
+    {
+      data = [oldRecord objectForKey: @"c_domain"];
+      if (data)
+        [newRecord setObject: data forKey: @"c_domain"];
+    }
+
   data = [oldRecord objectForKey: @"mail"];
   if (!data)
     data = @"";