Fix pistons permanently breaking server-wide on dedicated servers (#1420)

triggerEvent() set ignoreUpdate to true at the start but three early
return paths skipped the reset at the end. Once any of these paths was
hit, the TLS flag stayed true permanently, blocking all piston neighbor
updates for the rest of the server session.

Minecraft.World/PistonBaseTile.cpp

@@ -218,10 +218,12 @@ bool PistonBaseTile::triggerEvent(Level *level, int x, int y, int z, int param1,
 		if (extend && param1 == TRIGGER_CONTRACT)
 		{
 			level->setData(x, y, z, facing | EXTENDED_BIT, UPDATE_CLIENTS);
+			ignoreUpdate(false);
 			return false;
 		}
 		else if (!extend && param1 == TRIGGER_EXTEND)
 		{
+			ignoreUpdate(false);
 			return false;
 		}
 	}
@@ -247,6 +249,7 @@ bool PistonBaseTile::triggerEvent(Level *level, int x, int y, int z, int param1,
 		}
 		else
 		{
+			ignoreUpdate(false);
 			return false;
 		}
 		PIXEndNamedEvent();