Seg fault fix

src/workers/Hashrate.cpp

@@ -50,7 +50,7 @@ inline static const char *format(double h, char *buf, size_t size)
 
 Hashrate::Hashrate(size_t threads, xmrig::Controller *controller) :
     m_highest(0.0),
-    m_threads(threads),
+    m_threads(0),
     m_timer(nullptr)
 {
     set_threads(threads);