Missing #include <cstdio> in networkTracker.cpp

[pope-es]

In Ubuntu 20.04, when building, make complains about "stderr" and "fprintf" in networkTracker.cpp.

Adding #include solved the issue.

[kesheldr]

I don't know why that was complaining but the #include for stdio.h has been added now so hopefully fixed. Let me know.

[MarioHewardt]

Closing for now. Please reopen if the issue persists with the latest changes.