Fixes MicrosoftDocs/azure-docs#114367

Updated Source slot to target slot. It used to say way for every source instance to restart but that doesn't make sense. You are waiting for the target instances to restart after taking the new information.

Author: BryanTrach-MSFT

articles/app-service/deploy-staging-slots.md

@@ -103,7 +103,7 @@ When you swap two slots (usually from a staging slot into the production slot),
 
     Any of these cases trigger all instances in the source slot to restart. During [swap with preview](#Multi-Phase), this marks the end of the first phase. The swap operation is paused, and you can validate that the source slot works correctly with the target slot's settings.
 
-1. Wait for every instance in the source slot to complete its restart. If any instance fails to restart, the swap operation reverts all changes to the source slot and stops the operation.
+1. Wait for every instance in the target slot to complete its restart. If any instance fails to restart, the swap operation reverts all changes to the source slot and stops the operation.
 
 1. If [local cache](overview-local-cache.md) is enabled, trigger local cache initialization by making an HTTP request to the application root ("/") on each instance of the source slot. Wait until each instance returns any HTTP response. Local cache initialization causes another restart on each instance.