[CE] UI fails silently when collecting logs

Summary
Collecting logs from UI is broken on CE. It fails silently. 
Checking the network tab, we can see that UI is making a payload request as follows:

nodes=ns_1%40172.23.122.100%2Cns_1%40172.23.122.101%2Cns_1%40172.23.122.102%2Cns_1%40172.23.122.103&logRedactionLevel=null&uploadHost=uploads.couchbase.com&customer=trial&ticket=

(to controller/startLogsCollection)
As we see, logRedactionLevel=null and hence ns-server seems to be responding back with 

{"logRedactionLevel":"log redaction should be none or partial"}

For steps to repro, and logs see MB-51205