Stats: initialize start_time automatically

src/Stats.cxx

@@ -34,7 +34,7 @@
  * The monotonic time stamp when MPD was started.  It is used to
  * calculate the uptime.
  */
-static unsigned start_time;
+static const unsigned start_time = MonotonicClockS();
 #endif
 
 #ifdef ENABLE_DATABASE
@@ -47,17 +47,6 @@ enum class StatsValidity : uint8_t {
 
 static StatsValidity stats_validity = StatsValidity::INVALID;
 
-#endif
-
-void stats_global_init(void)
-{
-#ifndef WIN32
-	start_time = MonotonicClockS();
-#endif
-}
-
-#ifdef ENABLE_DATABASE
-
 void
 stats_invalidate()
 {