Fix spawning 1 crate too much if maximum == minimum

If Maximum == Minimum but 'crates' < Maximum, the formula would simply return min + 1 regardless of max being identical to min.
Only adding 1 more crate if Maximum is higher than Minimum fixes that.

OpenRA.Mods.Common/Traits/World/CrateSpawner.cs

@@ -119,7 +119,7 @@ namespace OpenRA.Mods.Common.Traits
 				ticks = info.SpawnInterval;
 
 				var toSpawn = Math.Max(0, info.Minimum - crates)
-					+ (crates < info.Maximum ? 1 : 0);
+					+ (crates < info.Maximum && info.Maximum > info.Minimum ? 1 : 0);
 
 				for (var n = 0; n < toSpawn; n++)
 					SpawnCrate(self);