Find out why date_head is missing from some projects

[rimutaka]

The front end was failing because date_head was missing from projects.

Example:

"project_name" : "LeetCode",
"github_user_name" : "EINDEX",
"github_repo_name" : "LeetCode",
"date_init" : "2019-01-03T14:52:23+08:00",

• https://stackmuncher.com/EINDEX
• https://stackmuncher.com/KvanTTT

I added a check to filter out such projects because something's off there, so no harm in skipping them for now. See stackmuncher/stm_server@b05f151