Remove redundant static uint32_t QWaylandDisplay::currentTimeMillisec()

Fortunately it was unused. Its 32-bit unsigned return type, measuring
time in milliseconds, wraps around every 50 days. If Qt Wayland ever
does need to know the current time in milliseconds, I can recommend
QDateTime::currentMSecsSinceEpoch().

Change-Id: I03e70e3c7060b1e8fb82fc2e151bb187b6598b96
Reviewed-by: David Edmundson <davidedmundson@kde.org>

src/plugins/platforms/wayland/qwaylanddisplay.cpp

@@ -858,16 +858,6 @@ void QWaylandDisplay::removeListener(RegistryListener listener, void *data)
     mRegistryListeners.erase(iter, mRegistryListeners.end());
 }
 
-uint32_t QWaylandDisplay::currentTimeMillisec()
-{
-    //### we throw away the time information
-    struct timeval tv;
-    int ret = gettimeofday(&tv, nullptr);
-    if (ret == 0)
-        return tv.tv_sec*1000 + tv.tv_usec/1000;
-    return 0;
-}
-
 void QWaylandDisplay::forceRoundTrip()
 {
      wl_display_roundtrip(mDisplay);

src/plugins/platforms/wayland/qwaylanddisplay_p.h

@@ -226,8 +226,6 @@ public:
 
     QWaylandShm *shm() const { return mShm.data(); }
 
-    static uint32_t currentTimeMillisec();
-
     void forceRoundTrip();
 
     bool supportsWindowDecoration() const;