Satisfy derived class compatibility

Derived class must not use throw specifiers looser than the base class (including default), and in C++03 std::runtime_error has explicit 'throw()' (empty) specifier for the destructor.

Author: kkorotkov

include/netlicensing/exception.h

@@ -40,6 +40,8 @@ class RestException : public std::runtime_error {
  public:
   RestException(const std::list<Info>& details, int code) : 
     std::runtime_error("REST error"), code_(code), details_(details) {}
+ 
+  virtual ~RestException() throw() {}
 
   int http_code() const {
     return code_;