Move logs related to TCP Healthcheck from AWS ELBs to Debug Mode

[aelkugia]

Description

Customer is seeing the following logs during normal runtime:

http: TLS handshake error from .....: EOF" file="runtime/asm_amd64.s:2198" func=runtime.goexit

These are because of TCP healthchecks from AWS ELBs, we should just move these related logs to debug mode level.

Related internal zendesk ticket: #204