add a missing ')' on dialogs unknown owner name

diff --git a/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs b/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs
index eac36fb..927ea33 100644
--- a/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs
+++ b/OpenSim/Region/CoreModules/Avatar/Dialog/DialogModule.cs
@@ -153,7 +153,7 @@ namespace OpenSim.Region.CoreModules.Avatar.Dialog
             }
             if(string.IsNullOrEmpty(ownerFirstName))
             {
-                ownerFirstName = "(unknown";
+                ownerFirstName = "(unknown)";
                 ownerLastName = string.Empty;
             }
         }