[tmva][sofie] Fix adding standard library header

Remove check to include standard library header only if within a list of allowed ones.
There is no need for that check and this was excluding addition of extra headers like chrono

Author: lmoneta

tmva/sofie/inc/TMVA/RModel_Base.hxx

@@ -82,10 +82,8 @@ public:
    }
    void AddNeededStdLib(std::string libname)
    {
-      static const std::unordered_set<std::string> allowedStdLib = {"vector", "algorithm", "cmath", "memory", "span"};
-      if (allowedStdLib.find(libname) != allowedStdLib.end()) {
-         fNeededStdLib.insert(libname);
-      }
+      // if the library is already in the set, insert does nothing, so we don't need to check before inserting
+      fNeededStdLib.insert(libname);
    }
    void AddNeededCustomHeader(std::string filename)
    {