CRAN: fix donttest issue by 2022-10-30

[tanho63]

https://cran.r-project.org/web/checks/check_results_ffsimulator.html https://www.stats.ox.ac.uk/pub/bdr/donttest/ffsimulator.out

* checking examples with --run-donttest ... [200s/241s] ERROR
Running examples in ‘ffsimulator-Ex.R’ failed
The error most likely occurred in:

> ### Name: ffs_rosters
> ### Title: Get Rosters
> ### Aliases: ffs_rosters ffs_rosters.mfl_conn ffs_rosters.sleeper_conn
> ###   ffs_rosters.flea_conn ffs_rosters.espn_conn
> 
> ### ** Examples
> 
> ## No test: 
> # cached examples
> conn <- .ffs_cache("mfl_conn.rds")
> 
> ffs_rosters(conn)
Request failed [429]. Retrying in 1 seconds...
Request failed [429]. Retrying in 1.5 seconds...
Error: You've hit the MFL rate limit wall! Please adjust the
built-in rate_limit arguments in mfl_connect()!
Execution halted