I can't recall with 100% certainty if I bought the glue, but it's not in my inventory nor in the store.
Danny doesn't have an option to call Clara out. He only appears in the day time in the hallway with the option to "Check out Danny".
Someone mentioned to just progress the quests and it'll show up in the store eventually but my quest log is empty as I've pretty much caught up to all the content up to v0.22
Yeah Danny would be by the girls bathroom if the quest could be completed. Hate to say this but I don't know of any one so far that completed Jessica's rout before doing Clara, it is probable that buying the mints for Jessica's rout replaced the glue. Similar to what happens with the key for the snooping quest.
Its not really your fault, Uber has something wrong with the inventory system after you get something there should be no way it could be replaced by another item, this is the cause of the key for Mary's room that goes missing and causes the snooping bug.
I guess you have the honor of finding yet another scenario where this inventory bug shows itself.
The only advice I can give is play the game again and don't do Jessica's quest before clearing at least the first 4 Clara events. Or wait for another update(lame for sure).
Even if you try what I suggested there is no guarantee the game will not bug in some other way all I can say is i made it through the entire update with out any bugs, been quite a few that have as well and quite a few that got bugged. Its a crap shoot to be honest.