[Bugfix][T106BUG-493]Fix can't setup datacall with IPV6 when username and password are empty

Only Configure: No
Affected branch: master
Affected module: data
Is it affected on both ZXIC and MTK: only ZXIC
Self-test: Yes
Doc Update: No

Change-Id: Ic96281603d429aaf1d71fb175f70b1a9f1c2028e
1 file changed