Pagination only shows the first two pages

[grunweg]

STR:
Visit https://jpeople.jacobs-cs.club/, search for "status:undergrad year:2018". Possibly wait for some time until results pop up. Scroll to the bottom of the page, click "Load more". Do so once or twice more. At this point, the last entry is "Catherine Schellstede" - 75 entries are showing so far..
Then click on the "Load more" button again.
Actual results:
The "Load more" button is dark blue - but clicking on it makes my fan kick in for a few seconds (so apparently something happens indeed), but no new people show up. Clicking repeatedly doesn't make this better.
Expected results:
I get shown more people - we have more than 75 freshies, and some freshies are definitely not present in the list.

Reproduced on Debian GNU/Linux Jessie, with Iceweasel (=Debian's version of Firefox) 38.3.0, in safe mode also.

[tkw1536]

1. "status:undergrad year:2018" should give 0 results, years are represented as YY in the database
2. "status:undergrad year:18" internally gives 245 results but only the first two pages are displayed

We need to redo pagination but no one has time to debug it atm.