reduce police roadblock monster spawns (#66266)

police roadblocks can spawn 20+ zed cops swat zeds etc combined with the
distraction offered by the nearby turrets and decent supply of guns and
ammo around in corpses and the back of police cars makes for a super
easy loot party, pretty much everyone in the road block is easy prey for
someone with half a working brain

reduce the zed spawns by half, the special still gives a good amount of
loot, the cars and corpses have good changes of setting up for a good
gunfight, just not as much anymore

Co-authored-by: casswedson <[email protected]>

data/json/mapgen/map_extras/roadblock.json

@@ -47,7 +47,7 @@
         { "vehicle": "policecar", "x": 18, "y": 10, "chance": 100, "status": 1 },
         { "vehicle": "policecar", "x": 16, "y": 17, "chance": 100, "status": 1 }
       ],
-      "place_monster": [ { "group": "GROUP_POLICE_EXTRA", "x": [ 0, 23 ], "y": [ 0, 23 ], "repeat": [ 5, 12 ] } ],
+      "place_monster": [ { "group": "GROUP_POLICE_EXTRA", "x": [ 0, 23 ], "y": [ 0, 23 ], "repeat": [ 3, 6 ] } ],
       "place_loot": [
         { "group": "cop_armory", "x": 9, "y": [ 6, 7 ], "chance": 100, "repeat": [ 0, 9 ] },
         { "group": "cop_armory", "x": 16, "y": [ 10, 11 ], "chance": 100, "repeat": [ 0, 9 ] },