refactor: Replace RecursiveMutex with Mutex in netbase.cpp
refactor: Replace RecursiveMutex with Mutex in netbase.cpp

Former-commit-id: 8cc43853f354320656999cd250fc31428e390e24
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin