fix bug: input

workflow.wdl

     File ref_dir
     String fasta
 	String docker
-    String cluster
+    String cluster_config
     String disk_size
 
 	call access.access as access {
 		fasta=fasta,
 		ref_dir=ref_dir,
 		docker = docker,
-		cluster = cluster,
+		cluster_config = cluster_config,
 		disk_size = disk_size
 	}
 
 		bed = bed,
 		access_bed = access.access_bed,
 		docker = docker,
-		cluster = cluster,
+		cluster_config = cluster_config,
 		disk_size = disk_size
 	}
 
 		input:
 		result = batch.result,
 		docker = docker,
-		cluster = cluster,
+		cluster_config = cluster_config,
 		disk_size = disk_size
 	}
 }