This way we avoid triggering timers and doing extra poll loops for each
BTS which is configured but not up. It also has the effect of removing
logging about estimating paging buffers for BTS which are down, which
can be confusing.
Furthermore, since work is delayed until the TRX and cell in general is
configured, the first estimation is properly done now since the correct
configuration is in place at that time.
Related: SYS#5922
Change-Id: I1b5b1a98115b4e9d821eb3330fc5b970a0e78a44
Reaching this point will only make system load (CPU, mem) grow, making
it hard for the process to keep up with work to do, with no benefit
since the requests will anyway be scheduled too late.
Related: SYS#5922
Change-Id: I6523c6816a4d16b71084d004e979be40cf0aeeb0