Catch empty ref images (#1397)

* slow down constant reboots caused by the flow. With this, after a restart due to exception/panic the first round gets delayed by 5 minutes

* catch empty reference images

* .

Co-authored-by: CaCO3 <caco@ruinelli.ch>

code/components/jomjol_helper/Helper.h

@@ -7,6 +7,7 @@
 using namespace std;
 
 std::string FormatFileName(std::string input);
+std::size_t file_size(const std::string& file_name);
 void FindReplace(std::string& line, std::string& oldString, std::string& newString);
 
 bool CopyFile(string input, string output);