Automatic merge from submit-queue

fix system language judging bug in loadSystemLanguage
Signed-off-by: allencloud <allen.sun@daocloud.io>



**What this PR does / why we need it**:
This PR removes some unused code in loadSystemLanguage. Since in code `pieces := strings.Split(langStr, ".")`, even `langStr` is an empty string, `piece` is a slice with one element of empty string, so there is no chance that len(pieces) == 0.

According to these, I think it is OK to remove the unused code in loadSystemLanguage.

According to the discuss we had, finally we decided to use a more accurate way to change the code, using `if len(pieces) != 1` to make the decision. 

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
NONE

**Special notes for your reviewer**:
NONE

**Release note**:

```release-note
NONE
```