Remove 6.Dingor mission

This is identical to the lingor mission. The only change is "ibr_dingor"
added in mission.sqm. Admins can use the lingor files for dingor. The
two maps are the same apart from the desert skin. There are currently no
servers running dingor at the time of writing this.

Server Files/MPMissions/DayZ_Epoch_7.Lingor/mission.sqm

@@ -33,7 +33,8 @@ class Mission
 		"pook_h13",
 		"csj_gyroac",
 		"map_eu",
-		"jetskiyanahuiaddon"
+		"jetskiyanahuiaddon",
+		"redryder"
 	};
 	addOnsAuto[]=
 	{