gplugin/gplugin

Add some additional error checking to gplugin_native_loader_query

Testing Done:
Ran the unit tests

Reviewed at https://reviews.imfreedom.org/r/1848/
EionRobb <> EionRobb <eion@robbmob.com>
ivanhoe <107501-ivanhoe@users.noreply.gitlab.com> ivanhoe <ivanhoe@fiscari.de>
Richard Laager <rlaager@pidgin.im> <rlaager@wiktel.com>