`list_surveys()` does not return a complete list

[sbfnk]

Probably related to #90

library("socialmixr")
#> 
#> Attaching package: 'socialmixr'
#> The following object is masked from 'package:utils':
#> 
#>     cite
list_surveys()
#> Warning in eval(jsub, SDenv, parent.frame()): NAs introduced by coercion
#>    date_added                                                   title
#> 1: 2017-12-07 Social contact data before and during COVID-19 in China
#>           creator  url
#> 1: Zhang Juanjuan <NA>

^{Created on 2023-10-18 with reprex v2.0.2}