Merge pull request 'spam in logs of "Error Undefined variable in expression: _grp"' (#1) from fix/patrol-spawn into master

Reviewed-on: #1

src/scripts/server/patrols/manage_one_patrol.sqf

@@ -1,5 +1,5 @@
 params [ "_minimum_readiness", "_is_infantry" ];
-private [ "_headless_client" ];
+private [ "_headless_client", "_grp", "_spawn_marker", "_sector_spawn_pos", "_started_time", "_patrol_continue" ];
 
 waitUntil { !isNil "blufor_sectors" };
 waitUntil { !isNil "combat_readiness" };
@@ -58,6 +58,11 @@ while { GRLIB_endgame == 0 } do {
     };
 
     while { _patrol_continue } do {
+        if (isNil "_grp") then {
+            _patrol_continue = false;
+            ["_grp was nil, but patrol was expected", "MANAGE_ONE_PATROL"] call KPLIB_fnc_log;
+            break;
+        };
         sleep 60;
         if ( count (units _grp) == 0  ) then {
             _patrol_continue = false;