Reorder a g_object_get to not break pidgin.

`g_object_get` will stop at the first error. Pidgin hadn't yet been updated for
the author-name-color property which lead to the timestamp not being filled out
by `g_object_get` and thus broke all messages in Pidgin 3.

Testing Done:
I tested this in the Pidgin tree and then rebuilt it in the talkatu tree.

Reviewed at https://reviews.imfreedom.org/r/753/