Update Relx to v3.24.5
Update Relx to v3.24.5

I've built and uploaded the newest Relx to https://erlang.mk
Next time this is necessary I should add a Makefile target to
do it automatically.

jj1bdx/erlang.mk,ninenines/erlang.mk,rabbitmq/erlang.mk,crownedgrouse/erlang.mk