Update player lerpoldxp/yp in moveplayer()

Just like gotoposition(), the player would otherwise appear to "zip"
after the command got run. This did not happen in the previous loop
order.

desktop_version/src/Script.cpp

@@ -107,6 +107,8 @@ void scriptclass::run(void)
 				{
 					obj.entities[player].xp += ss_toi(words[1]);
 					obj.entities[player].yp += ss_toi(words[2]);
+					obj.entities[player].lerpoldxp = obj.entities[player].xp;
+					obj.entities[player].lerpoldyp = obj.entities[player].yp;
 				}
 				scriptdelay = 1;
 			}