refactor: Move "--old-args" check into manage profiles dialog

[buhtz]

Notifier for me.
Move that "--old-args" check into the Manage Profiles dialog code. Check for focusOutEvent event to validate the QTextEdit content.

backintime/common/config.py

Lines 1211 to 1225 in 525da07

	def rsyncOptions(self, profile_id = None):
	#?rsync options. Options must be quoted e.g. \-\-exclude-from="/path/to/my exclude file"
	val = self.profileStrValue('snapshots.rsync_options.value', '', profile_id)
	if '--old-args' in val:
	logger.warning(
	'Found rsync flag "--old-args". That flag will be removed '
	'from the options because it conflicts with '
	'the flag "-s" (also known as "--secluded-args" or '
	'"--protected-args") which is used by Back In Time to force '
	'the "new form of argument protection" in rsync.'
	)
	val = val.replace('--old-args', '')
	return val

Background: To improve code structure and logic related to replacing config management (#1850).