clean-tsv: Improve --sort-col error message

The existing error message prints the python ValueError after the
helpful, custom error message we've written. This can easily get lost
on the user. Because there's no real need to share the underlying error
(since this error is pretty well scoped), stop printing it to stderr.

bin/clean-tsv

@@ -48,9 +48,9 @@ def clean_tsv_file(input_file, output_file, n_cols, header, sort_col):
             if not header:
                 sort_col = int(sort_col)
             col_names.remove(sort_col)
-        except ValueError as e:
-            print(f"{sort_col} is not a column name in file, or if --no-header was used, there are not this many columns in the file.")
-            raise e
+        except ValueError:
+            raise ValueError(f"«{sort_col}» is not a column name in file, or if --no-header was "
+                "used, there are not this many columns in the file.")
         col_names = [sort_col] + col_names
     data = data.sort_values(col_names)
     data.to_csv(output_file, sep="\t", index=False, header=header, quoting=csv.QUOTE_NONE)