updated DB_version number

code_boost/src/cxx/statistics_db.h

@@ -23,7 +23,7 @@ public:
     /*
      * Database version: Increment number on every change in the C++ code!
      */
-    static const int DB_VERSION = 3;
+    static const int DB_VERSION = 4;
 
     /*
      * Methods for writing values into database