bashism in /bin/sh script

[onlyjob]

As reported in ​https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=772390

checkbashisms (from the 'devscripts' package) found the following:

possible bashism in ./usr/lib/winswitch/bin-override/xdg-open line 28
(should be 'b = a'):
		  if [ $e == 0 ]; then

Not using bash (or a Debian Policy compliant shell interpreter that doesn't provide such an extra feature) as /bin/sh is likely to lead to errors or unexpected behaviours.
Please be aware that dash is the default /bin/sh in Debian.

Hints about how to fix bashisms can be found at:
​https://wiki.ubuntu.com/DashAsBinSh

[Antoine Martin]

Applied in r5310. Closing. (sorry about the delay)