Sync code with .env in build.rs

[dynco-nym]

Keep dotenv file always up to date

index 2be5300bd..e40e54a47 100644
--- a/envs/mainnet.env
+++ b/envs/mainnet.env
@@ -25,4 +25,4 @@ NYXD="https://rpc.nymtech.net"
-NYM_VPN_API="https://nymvpn.net/api/"
+NYM_VPN_API="https://nymvpn.com/api"

... and we already see its use case :)

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This change is