default: do not warn if slapos_promise is not set

slapos/recipe/build/__init__.py

@@ -98,7 +98,6 @@ class Script(EnvironMixin):
   def _checkPromise(self, promise_key, location):
     promise_text = self.options.get(promise_key)
     if promise_text is None:
-      self.logger.warning('Warning, promise %r not defined' % promise_key)
       return True
     promise_problem_list = []
     a = promise_problem_list.append