[PATCH 6/7] lib-sieve: Log a warning when cumulative CPU exceeds the limit

[PATCH 6/7] lib-sieve: Log a warning when cumulative CPU exceeds the limit

sieve_binary_record_resource_usage() returned FALSE when the script's
cumulative CPU time crossed sieve_max_cpu_time, but the only log line
on that path was a debug-level "Updated cumulative resource usage"
emitted on every recording, with no signal at the actual disable
transition. Operators had to infer the disable from later "Failed to
open script ... (cumulative resource limit exceeded)" errors on
subsequent deliveries.

Emit a warning at the transition point, including the cumulative CPU
usage that triggered it.

Gbp-Pq: Name 0006-lib-sieve-Log-a-warning-when-cumulative-CPU-exceeds-.patch