weBapp/JS: add missing encoding step for attribute request reason
weBapp/JS: add missing encoding step for attribute request reason

Without this, the string was directly embedded into the query-string formated POST data
- and an "&" character would split the value being passed.

University-of-Auckland/federationregistry2-Tuakiri,University-of-Auckland/federationregistry2-Tuakiri,REANNZ/federationregistry2-Tuakiri,University-of-Auckland/federationregistry2-Tuakiri,REANNZ/federationregistry2-Tuakiri,REANNZ/federationregistry2-Tuakiri,REANNZ/federationregistry2-Tuakiri,REANNZ/federationregistry2-Tuakiri,University-of-Auckland/federationregistry2-Tuakiri,University-of-Auckland/federationregistry2-Tuakiri