Merge pull request #3337 from JohnAFernandez/Interpolation-Bug

Fix a rare but eventual crash in the interpolation code.

Author: JohnAFernandez

code/network/multi_obj.cpp

@@ -3387,7 +3387,7 @@ void multi_oo_calc_interp_splines(int player_id, object* objp, matrix *new_orien
 	float delta = multi_oo_calc_pos_time_difference(player_id, net_sig_idx);
 	// if an error or invalid value, use the local timestamps instead of those received. Should be rare.
 	if (delta <= 0.0f) {
-		delta = (float)(timestamp() - Oo_info.received_frametimes[player_id].at(Oo_info.interp[net_sig_idx].pos_timestamp)) / TIMESTAMP_FREQUENCY;
+		delta = (float)(timestamp() - Oo_info.interp[net_sig_idx].pos_timestamp) / TIMESTAMP_FREQUENCY;
 	}
 
 	Oo_info.interp[net_sig_idx].pos_time_delta = delta;