Properly deal with classes destructors

There are some classes such as AuditLog that demands a reference count. That is
needed because this class can be used by different instances of the Rules
classes.

src/audit_log_writer.cc

@@ -38,4 +38,5 @@ bool AuditLogWriter::write(Assay *assay, int parts) {
     return true;
 }
 
+
 }  // namespace ModSecurity