Auto merge of #10442 - Urgau:git2-update, r=alexcrichton

Update git2 dependencies

This pull-request update git2 to 0.14.1 and git2-curl to 0.15.0 and libgit2-sys to 0.13.1.

This fix a memory corruption that I have locally when running the testsuite:
```
==2338650==  Uninitialised value was created by a stack allocation
==2338650==    at 0x11FE3A0: git2::remote::Remote::fetch (remote.rs:276)
```

diff --cc Cargo.toml
Simple merge