docker push failed due to "Error pushing to registry: Authentication is required." if build(buildconfig) created first

**NOTE:** It might be expected behaivor, but please allow me to file the report.
## Env

```
# openshift version
openshift v1.0.5-200-gc1c80c0
kubernetes v1.1.0-alpha.0-1605-g44c91b1
```
## Issue
- Please see Reproduce steps below.

**_(Removed reprodce steps, because I wrote wrong steps. I updated below)**_
