another constness fix

apps/openmw/mwworld/world.cpp

@@ -480,6 +480,11 @@ namespace MWWorld
         return (*mGlobalVariables)[name];
     }
 
+    Globals::Data World::getGlobalVariable (const std::string& name) const
+    {
+        return (*mGlobalVariables)[name];
+    }
+
     char World::getGlobalVariableType (const std::string& name) const
     {
         return mGlobalVariables->getType (name);

apps/openmw/mwworld/world.hpp

@@ -125,6 +125,8 @@ namespace MWWorld
 
             Globals::Data& getGlobalVariable (const std::string& name);
 
+            Globals::Data getGlobalVariable (const std::string& name) const;
+
             char getGlobalVariableType (const std::string& name) const;
             ///< Return ' ', if there is no global variable with this name.