Fix gzip bug.

workflows/components/filterbybam.py

@@ -58,7 +58,7 @@ def filter(reads_file, id_list_file, output_file):
     
     # Compress file
     if output_file.endswith(".gz"):
-        os.system("gzip" + output_file[:-3])
+        os.system("gzip " + output_file[:-3])
     
 
 class FilterByBam (Component):