pcu: Enable dl-tbf-idle-time and idle-ack-delay by default

Currently these are enabled in the default config file. Since CoDel
is enabled by default in main() but should not be used without at
least dl-tbf-idle-time, the current default config may lead to
packet loss and performance problems.

This commit enables both features to provide a good (GPRS) performance
experience even without a configuration.

Sponsored-by: On-Waves ehf

src/pcu_main.cpp

@@ -191,6 +191,8 @@ int main(int argc, char *argv[])
 	bts->cs_downgrade_threshold = 200;
 
 	bts->llc_codel_interval_msec = LLC_CODEL_USE_DEFAULT;
+	bts->dl_tbf_idle_msec = 2000;
+	bts->llc_idle_ack_csec = 10;
 
 	msgb_set_talloc_ctx(tall_pcu_ctx);