gitRepo: Fix an error due to missing TLS certificates

This was a problem when run inside a sandbox, e.g. via
"fetchRepoProject". The error message from repo seems unrelated:

fatal: Cannot get https://gerrit.googlesource.com/git-repo/clone.bundle
fatal: error no host given

But the exception is actually thrown due to missing certificates
(/etc/ssl/certs). It should be possible to provide another location via
environment variables (e.g. SSL_CERT_FILE, REQUESTS_CA_BUNDLE or
CURL_CA_BUNDLE) but apparently that doesn't actually work for some
reason (would have to study our Python packaging).

Now "fetchRepoProject" works without the "--no-clone-bundle" option.

pkgs/build-support/fetchrepoproject/default.nix

@@ -21,8 +21,6 @@ let
     "--manifest-url=${manifest}"
     "--manifest-branch=${rev}"
     "--depth=1"
-    #TODO: fetching clone.bundle seems to fail spectacularly inside a sandbox.
-    "--no-clone-bundle"
     (optionalString createMirror "--mirror")
     (optionalString useArchive "--archive")
   ] ++ extraRepoInitFlags;