handling incorrect captcha and check not found cases

exceptions/ofdrequestexception.cpp

@@ -0,0 +1,6 @@
+#include "ofdrequestexception.h"
+
+OfdRequestException::OfdRequestException(const char* msg) : message(msg) {}
+const char* OfdRequestException::what() throw() {
+    return message.c_str();
+}