Update gateway URL to default for helloc example

- this caused confusion for a user who had logged in for
"127.0.0.1", but not for "localhost" then saw an error when
deploying and trying to access "localhost" for which there
was no credential available.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

sample-functions/CHelloWorld/stack.yml

@@ -1,9 +1,9 @@
 provider:
   name: faas
-  gateway: http://localhost:8080
+  gateway: http://127.0.0.1:8080
 
 functions:
   helloc:
     lang: Dockerfile
     handler: ./src
-    image: alexellis/helloc
+    image: alexellis/helloc:0.1