gameplay: don't increment MvM revives stat between rounds

when the game is not in active play, we shouldn't count any
revives. revives during this time are irrelevant and often happen
for jokes.

the revive stat also causes a revive speed penalty for each
revive done, so these irrelevant revives should not count against that.

ref: ValveSoftware/Source-1-Games#4782

src/game/shared/tf/tf_revive.cpp

@@ -384,8 +384,12 @@ bool CTFReviveMarker::ReviveOwner( void )
 
 	m_hOwner->ForceRespawn();
 
-	// Increment stat
-	CTF_GameStats.Event_PlayerRevived( m_hOwner );
+	// Don't count revives when the game isn't in active play
+	if ( TFGameRules()->State_Get() != GR_STATE_BETWEEN_RNDS )
+	{
+		// Increment stat
+		CTF_GameStats.Event_PlayerRevived( m_hOwner );
+	}
 
 	// If the medic's gone, or dead, stay in the spawn room
 	if ( !m_pReviver || !m_pReviver->IsAlive() )