Handle different system names of w32 in Tramp (Bug#38079)

* lisp/net/tramp.el (tramp-restricted-shell-hosts-alist):
Initialize with `system-name' in small and capital chars.
1 job for master in 62 minutes and 46 seconds (queued for 5 seconds)
Status Job ID Name Coverage
failed #4142


Name Stage Failure
test-all Test
Makefile:319: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
make[1]: *** [check-expensive] Error 2
Makefile:294: recipe for target 'check-expensive' failed
make[1]: Leaving directory '/builds/emacs/emacs/test'
make: *** [check-expensive] Error 2
Makefile:959: recipe for target 'check-expensive' failed
ERROR: Job failed: exit code 1