Fix to: Adding ability to explicitly define join clause

There was a bug in this condition: <cfif
variables.instance.jointables[local.i] eq jointable>.
variables.instance.jointables[local.i] is a struct that contains
"table" variable, so the updated statement is: <cfif
variables.instance.jointables[local.i].table eq jointable>.
Merge pull request #1678 from rabdulhaq/candidate

Fix to: Adding ability to explicitly define join clause