FIREFLY-166: fixed condition when Link Substitution fails, table fail to load.

[loitly]

https://jira.ipac.caltech.edu/browse/FIREFLY-166

When VOTable Link contains bad column reference, table should not fail to load.
This fix applies to both href and value substitution. When the substitution fail to resolve, it will use what is given.

To test:
https://irsawebdev9.ipac.caltech.edu/FIREFLY-166_link_substitution_error_handling/firefly/

• upload the attached file in the ticket. In the 4th column, the 5th links should say
  info-${non-existing-column}-NGC6543, because non-existing-column is not a valid column in this table.

[wmiipac]

tested, looks good. Thanks!

[ejoliet]

(ok, but in my local safari, firefox and chrome, i've tried to upload the table but it keep spinning...) - aprat from that, i also realized that the result table in the viewer shows extra column ID that looks suspiciously the continuation of the table_name... but is not part of the original VOtable.

[loitly]

(ok, but in my local safari, firefox and chrome, i've tried to upload the table but it keep spinning...) - aprat from that, i also realized that the result table in the viewer shows extra column ID that looks suspiciously the continuation of the table_name... but is not part of the original VOtable.

@ejoliet this sound like an issue not related to this PR. Can I go ahead and merge this PR and you create a new ticket for the issues you found?

[ejoliet]

Ok, np, i'll create a new ticket. Thanks.