fixed minor bug in quickstart/sepolia

Author: LandauRaz

components/Starknet/modules/quick-start/pages/sepolia.adoc

@@ -108,7 +108,7 @@ Unlike when using a Starknet Devnet instance, there's no need for us to declare
 ----
 starkli declare \
     target/dev/hello_starknet_HelloStarknet.contract_class.json \
-    --network=sepolia
+    --network=sepolia \
     --strk
 ----