Multiple db connections opened for sqlite

[nonvis]

Describe the bug
sqlite only supports max_open_conn=1, but there are several instances where multiple db connections are opened.

To Reproduce
Steps to reproduce the behavior:

1. Open any questions page and up/down vote a comment
2. Now the website should be very unresponsive as there are processes in blocked state

Expected behavior
Pressing up/down vote buttons should not slow down the website.

Platform (please complete the following information):

• Device: Desktop
• OS: macOS
• Browser: chrome
• Version: 1.1.0

Source code analysis
vote_repo.go (line 78)

• session.Context(ctx) is called -> new db connection
• then, at line 90, vr.CheckRank() is called which eventually calls configService.GetConfigByKey, creating another db connection

There are several other instances of this behavior.
I think GetConfigByKey(ctx context.Context, key string)
should take session *Session, not ctx context.Context
Or we could have values from config table, loaded into cache on startup, so that config values could be read from cache all the time.

[LinkinStars]

Fix in v1.1.1