Validate new priorities count instead of DMX max

Author: dsmurfin

Sources/sACNKit/Merger/sACNMerger.swift

@@ -201,7 +201,7 @@ public class sACNMerger {
         guard let source = sources[sourceId] else { throw sACNMergerError.noSourceWithIdentifier(sourceId) }
 
         // priorities count must be valid and there must be priorities
-        guard newPrioritiesCount > 0 && newPrioritiesCount <= DMX.addressCount && newPriorities.count == DMX.addressCount else { throw sACNMergerError.invalidLevelCount }
+        guard newPrioritiesCount > 0 && newPrioritiesCount <= DMX.addressCount && newPriorities.count == newPrioritiesCount else { throw sACNMergerError.invalidLevelCount }
 
         let oldPerAddressPrioritiesCount = source.perAddressPriorityCount
         source.perAddressPriorityCount = newPrioritiesCount