Remove unused build_url function in data_utils

This commit removes build_url function in data_utils because there is no
user of this code. The using code of this function was removed at
 I1102859c871b8f16c284bdf7fba0f4346d50a63e .

Change-Id: I8989ac12f36f342ca1066cc65f7a427a83de721f
1 file changed