SPFilterDropdown incomplete error message

When having a CAMLQuery that refers to a wrong column name, the error returned is the same as the one if the relationsshipListColumn is wrong:

https://github.com/sympmarc/SPServices/blob/491f2d4dc13c5108dbfa1f8bcb775de8038d81e9/src/value-added/SPFilterDropdown.js#L104

Which can lead to a little confusion when trying to debug.