Fix player teleportation bug whilst sneaking

Only set back position when sneaking if player wasn't teleported by adding and using a bool "got_teleported" to player
it fixes #2876

src/player.h

@@ -318,6 +318,7 @@ public:
 	// Use a function, if isDead can be defined by other conditions
 	bool isDead() { return hp == 0; }
 
+	bool got_teleported;
 	bool touching_ground;
 	// This oscillates so that the player jumps a bit above the surface
 	bool in_liquid;