Fixed msvc2015/msys2 build & code cleanup.

src/net/Network.cpp

@@ -43,7 +43,6 @@
 
 
 xmrig::Network::Network(Controller *controller) :
-    m_controller(controller),
     m_donate(nullptr)
 {
     Workers::setListener(this);

src/net/Network.h

@@ -69,7 +69,6 @@ private:
 
     static void onTick(uv_timer_t *handle);
 
-    Controller *m_controller;
     IStrategy *m_donate;
     IStrategy *m_strategy;
     NetworkState m_state;