Remove TERM=dumb, which is causing difficult-to-reproduce hangs

Summary:
Ref T7119. Three users have now reported that this causes their systems to hang, so it's looking like the cure is worse than the disease.

Revert this until we can eventually reproduce and understand the hang.

Test Plan: Users running into issues have reported that this resolves things.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7119

Differential Revision: https://secure.phabricator.com/D11644

scripts/repository/commit_hook.php

@@ -1,14 +1,13 @@
-#!/usr/bin/env TERM=dumb php
+#!/usr/bin/env php
 <?php
 
-// NOTE: Note that we're specifying TERM=dumb above when invoking the PHP
-// interpreter. This suppresses an error which looks like this:
+// NOTE: This script will sometimes emit a warning like this on startup:
 //
 //   No entry for terminal type "unknown";
 //   using dumb terminal settings.
 //
-// This arises from somewhere in the PHP startup machinery if TERM is not
-// set to a recognized value.
+// This can be fixed by adding "TERM=dumb" to the shebang line, but doing so
+// causes some systems to hang mysteriously. See T7119.
 
 // Commit hooks execute in an unusual context where the environment may be
 // unavailable, particularly in SVN. The first parameter to this script is