kaccess: Actually reparse the config files when asked

This allows users to change accessibility settings (like turning on the screen reader) and have the settings take effect immediately. What actually happens is when the accessibility KCM settings are saved, it uses the same DBus activable trickery some of our other applications use. When the existing the existing KAccess instance is activated, it's told to check the settings again. But this doesn't actually happen:

An easy way to test this is to put a debug line inside of KAccessApp::setScreenReaderEnabled. Then, launch one instance. In a Kate window, open up kaccessrc and paste this into it:

[ScreenReader]
Enabled=true

(Doing this same process in the KCM also works, if you have that.)

Then spawn another process of kaccess, and watch as it fails to reload the config file. (Sometimes on will stay on, even if you turn it off and vice versa.) This patch makes this process less troublesome, and more reliable.