fix client install comunication

msql_acces.h

@@ -16,6 +16,7 @@ public:
   std::list<std::string> get_pinfo();
   void write_install(std::string package, std::string user);
   void write_remove(std::string);
+  bool get_package_exists(std::string package);
 private:
   sql::Connection *con;
   sql::Driver *driver;