Remove -f in vaf_ncm.wdl

tasks/vaf_ncm.wdl

@@ -10,11 +10,11 @@ task vaf_ncm {
     set -e
     nt=$(nproc)
     export NCM_HOME=/opt/NGSCheckMate
-    
+
     mkdir -p /ncm/fastq_vaf
     cp ${sep=" " vaf} /ncm/fastq_vaf
 
-    python /opt/NGSCheckMate/vaf_ncm.py -f -I /ncm/fastq_vaf/ -O . -nz $nt
+    python /opt/NGSCheckMate/vaf_ncm.py -I /ncm/fastq_vaf/ -O '.'' -nz $nt
   >>>
 
   runtime {