[connection] remove the `mode` attribute
It is now unused.
While removing mode, we also drop some sqlserver-specific reconnection logic snippets.
These had several downsides:
* untested
* partial coverage
* done at the wrong level
Related to #2919309.
@echo off
rem = """-*-Python-*- script
rem -------------------- DOS section --------------------
rem You could set PYTHONPATH or TK environment variables here
python -x "%~f0" %*
goto exit
"""
# -------------------- Python section --------------------
import sys
from os.path import join, dirname, normpath
sys.path.insert(0, normpath(join(dirname(__file__), '..', '..')))
from cubicweb.cwctl import run
run(sys.argv[1:])
DosExitLabel = """
:exit
rem """