Fix git commit-tree invokation for git v1.7.1
treebd386f4cca1879a3dfa344c8d2c60d39b8d1196f
-rwxr-xr-x 1127 ppg
-rwxr-xr-x 2126 ppg-apply
-rwxr-xr-x 1793 ppg-clone
-rwxr-xr-x 2729 ppg-commit
-rwxr-xr-x 584 ppg-init-dev
-rwxr-xr-x 856 ppg-init-goldsvr
-rwxr-xr-x 632 ppg-is-ancestor
-rwxr-xr-x 1437 ppg-pullapply
-rwxr-xr-x 2170 ppg-push-reports
-rwxr-xr-x 5140 ppg-repack
-rwxr-xr-x 1076 ppg-reports-to-dashboard
-rwxr-xr-x 2696 ppg-schedule
-rwxr-xr-x 2222 ppg-update-production
-rwxr-xr-x 1428 ppg-validate-staged-files