Swaziland has changed its name to Eswatini
Swaziland country has changed name to Eswatini so in CiviCRM it also has to be changed.
On 19 April 2018, King Mswati III announced that the Kingdom of Swaziland had renamed itself the Kingdom of Eswatini, reflecting the extant Swazi name for the state eSwatini, to mark the 50th anniversary of Swazi independence. The new name, Eswatini, [...]
Source: https://en.wikipedia.org/wiki/Eswatini#Independence_(1968%E2%80%93present)