cmd/go/testdata/script: delete trailing space in test

Addressing comment in golang.org/cl/212620. I submitted the
change before I addressed the comment.

Change-Id: I008fdb4fed1e0b2d24d739991fe10122695b90b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/213419
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

src/cmd/go/testdata/script/list_wildcard_skip_nonmatching.txt

@@ -2,7 +2,7 @@
 
 # First make sure that badpkg fails the list of '...'.
 ! go list ...
-stderr badpkg 
+stderr badpkg
 
 # Check that the list of 'm...' succeeds. That implies badpkg was skipped.
 go list m...