fix(docs): cast send -j requires # of threads (#716)

Author: timothymcmackin

pages/price-feeds/create-your-first-pyth-app/evm/part-2.mdx

@@ -116,7 +116,7 @@ We can do this using `cast` by running the following command:
 cast send \
   --private-key $PRIVATE_KEY \
   --rpc-url $RPC_URL \
-  -j \
+  -j 1 \
   --value 0.0005ether \
   $DEPLOYMENT_ADDRESS \
   "updateAndMint(bytes[])" \