SSL_ERROR_SYSCALL in connection to

While checking out the source from GitLab in Jenkin slave machine, I got below exception sometimes. But, At the same time, I can access the same project (via gitlab UI in the browser) in that slave machine.

15:31:14 stdout: 
15:31:14 stderr: fatal: unable to access '': OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to

I got the solution to fix this issue by upgrading the git from stack overflow. So, I just upgrade my git package from Git-2.12-64-bit to Git-2.14.2-64-bit in Jenkin slave machine and triggered the job. After that, it works, as usual. I do not why this is happening? Because it had been running correctly. My GitLab version is 9.3.6 and my Jenkin version is 2.77

Why is this happening? Because of internet problem or issue in git.exe or some other problem?