Remove CARGO_TEST_DISABLE_GIT_CLI

This was a leftover from the Appveyor days.

Author: ehuss

src/bootstrap/test.rs

@@ -289,8 +289,6 @@ impl Step for Cargo {
         // Don't run cross-compile tests, we may not have cross-compiled libstd libs
         // available.
         cargo.env("CFG_DISABLE_CROSS_TESTS", "1");
-        // Disable a test that has issues with mingw.
-        cargo.env("CARGO_TEST_DISABLE_GIT_CLI", "1");
         // Forcibly disable tests using nightly features since any changes to
         // those features won't be able to land.
         cargo.env("CARGO_TEST_DISABLE_NIGHTLY", "1");