Removed project_bases_legacy_from_git_repo_url from V8

This is not necessary because V8 is a Git-based project and relpath doesn't need
to be computed.

R=akuegel@chromium.org, machenbach@chromium.org
BUG=471767
LOG=N

Review URL: https://codereview.chromium.org/1149453002

Cr-Commit-Position: refs/heads/master@{#28481}

testing/commit_queue/config.json

@@ -5,7 +5,6 @@
     "git_repo_url": "https://chromium.googlesource.com/v8/v8",
     "hide_ref_in_committed_msg": true,
     "max_commit_burst": 1,
-    "project_bases_legacy_from_git_repo_url": true,
     "remote_branch": "refs/pending/heads/master",
     "rietveld_url": "https://codereview.chromium.org",
     "rietveld_user": "commit-bot@chromium.org",