Fixes for subscriber service.

build

@@ -1 +1 @@
-119
+120

src/MFAServer.h

@@ -35,7 +35,9 @@ namespace OpenWifi {
         static bool SendChallenge(const SecurityObjects::UserInfoAndPolicy &UInfo, const std::string &Method, const std::string &Challenge);
 
         static inline std::string MakeChallenge() {
-            return std::to_string(MicroService::instance().Random(1,999999));
+            char buf[16];
+            std::sprintf(buf,"%06llu",MicroService::instance().Random(1,999999));
+            return buf;
         }
 
     private: