install: Fix undefined variable pylint error

Signed-off-by: Euan Harris <euan.harris@citrix.com>
install: Fix pylint warnings

Signed-off-by: Euan Harris <euan.harris@citrix.com>
configure: Fix remaining pylint warnings

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge pull request #24 from euanh/planexsc

Another batch of trivial pylint warning fixes