fix an older "guides" nginx redirect

nginx/includes/redirects.conf

@@ -12,7 +12,7 @@ rewrite "^/docs/built-in-contracts/token$" "/docs/tokens/stellar-asset-contract"
 rewrite "^/docs/getting-started/deploy-to-a-local-network$" "/docs/getting-started/deploy-to-testnet" permanent;
 rewrite "^/docs/getting-started/deploy-to-futurenet$" "/docs/getting-started/deploy-to-testnet" permanent;
 rewrite "^/docs/tutorials/testing$" "https://developers.stellar.org/docs/learn/smart-contract-internals/debugging" permanent;
-rewrite "^/docs/category/how-to-guides$" "/docs/guides" permanent;
+rewrite "^/docs/category/how-to-guides$" "https://developers.stellar.org/docs/smart-contracts/guides" permanent;
 rewrite "^/docs/getting-started/connect-freighter-wallet$" "/docs/reference/freighter" permanent;
 rewrite "^/docs/common-interfaces/token$" "/docs/tokens/token-interface" permanent;
 rewrite "^/docs/how-to-guides/tokens$" "https://developers.stellar.org/docs/smart-contracts/example-contracts/tokens" permanent;