sync: fix os.environ logic errors
sync: fix os.environ logic errors

This is a dict to index, not a function to call.

Change-Id: I0117eeaaa8b2ef4762ab6f0d22f9ffdaee961f52
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/258132
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@google.com>
Reviewed-by: David Pursehouse <e7b5c6a4a3dbaca972851f8c075e19915752593f@collab.net>

aosp-mirror/tools_repo,codetutil/git-repo,lipro-yocto/git-repo,TheQtCompany/git-repo,lewixliu/git-repo,lewixliu/git-repo,GerritCodeReview/git-repo,GerritCodeReview/git-repo,lipro-yocto/git-repo,mer-tools/git-repo,mer-tools/git-repo,couchbasedeps/git-repo,aosp-mirror/tools_repo,codetutil/git-repo,TheQtCompany/git-repo,couchbasedeps/git-repo