Initializes a git_diff_format_email_options with default values.
git_diff_format_email_options
Equivalent to creating an instance with GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT.
The git_diff_format_email_options struct to initialize
Version of struct; pass GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION
GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION
Zero on success; -1 on failure.