CLEANUP: Remove wrong test manifests for gateway-tls-multiple

Those files are in test/integration/gateway-tls-multiple/manifests/tls_multiple/okmultiple/expectations/frontends and are duplicated here where they are not used.
Removing them.

Author: hdurand0710

.aspell.yml

@@ -59,6 +59,7 @@ allowed:
   - mutex
   - namespace
   - namespaces
+  - okmultiple
   - parallelize
   - passthrough
   - pid