alter judge condition

tasks/access.wdl

     String cluster_config
     String disk_size
 
+    Boolean amplicon = if (method == "amplicon") then true else false
+	
+
     command <<
-        if (${method}=="amplicon"); then
+        if ${amplicon}; then
             cp ${bed} access-mappable.bed
         else
             cnvkit.py access -s ${min_gap_size} -o access-mappable.bed ${fasta}