Fix missing include

[cschlack]

#include <git2/sys/transport.h> leads to the following error message:

compiling test.c
In file included from test.c:2:
/opt/homebrew/Cellar/libgit2/1.4.2_1/include/git2/sys/transport.h:38:9: error: unknown type name 'git_remote_connect_options'
                const git_remote_connect_options *connect_opts);
                      ^

git_remote_connect_options is defined in git2/remote.h

Including "git2/remote.h" in include/git2/sys/transport.h fixes the issue

[ethomson]

Good catch, thanks!