alter judge condition

tasks/access.wdl

@@ -7,9 +7,8 @@ task access {
     String docker
     String cluster_config
     String disk_size
+    Boolean amplicon = if (method == "amplicon") then "true" else "false"
 
-    Boolean amplicon = if (method == "amplicon") then true else false
-    
     command <<
         if ${amplicon}; then
             cp ${bed} access-mappable.bed