Filter build select causes an error when using ajax

[lindonb]

With the fix to issue #421 the filter build select no longer causes an error when ajax is not used, but there is still an error when ajax is used in version 2.14.1. It causes c.cache[tbodyIndex].row to be undefined at line 954 of jquery.tablesorter.widgets.js.

[Rob Garrison]

Hi @lindonb!

This error is caused by the same issue as #437, so it didn't get fixed this patch... but I'll get it in the next one!

[lindonb]

Thanks @Mottie!