Ensure the number of minutes is not < 1 for Redis setex
fix relationsToArray

The relationsToArray needs to unset it's relation value at the end of
every loop.
Merge pull request #6199 from Flightfreak/4.2

[4.2] Fixed "relationsToArray"
Merge pull request #5860 from lucasmichot/4.2-cache-redis-min-minutes

[4.2] Cache : ensure the number of minutes is not < 1 for Redis setex
Merge branch '4.2'