Refuse to create "dummy" service on "svcmgr create --template"

This could happen when the path is missing in the data sent to
the handler.

lib/node.py

@@ -3038,6 +3038,7 @@ def install_service(self, path, fpath=None, template=None,
             req = {
                 "action": "create",
                 "options": {
+                    "path": path,
                     "namespace": namespace,
                     "provision": provision,
                     "template": template,
@@ -3102,6 +3103,8 @@ def install_service(self, path, fpath=None, template=None,
                  # force the new path
                  for path, __data in _data.items():
                      break
+                 if path.endswith("svc/dummy"):
+                     raise ex.excError("no path in deployment data")
                  _data = {
                      path: __data,
                  }