Add support for different releases of Kubuntu

At some point the contents $DESKTOP_SESSION of changed in Kubuntu. This
change supports both the old and the new.

zshrc.d/44-kde-plasma-ssh-askpass.zsh

 # Use ksshaskpass if it exists and we're using the plasma desktop
-if [ "$DESKTOP_SESSION" = "/usr/share/xsessions/plasma" ]
+if [[ "$DESKTOP_SESSION" =~ "plasma" ]]
 then
 	if [ -x /usr/bin/ksshaskpass ]
 	then
@@ -10,4 +10,3 @@ then
 		echo "NOTICE: You're using the plasma desktop, but you don't have ksshaskpass installed?"
 	fi
 fi
-