Fix logic inversion with --git in --help

$ exa --help
[...]
  -@, --extended     display extended attribute keys and sizes

$ exa -@
Unrecognized option: '@'.

$ exa --extended
Unrecognized option: 'extended'.

$ exa --git
Option --git is useless without option --long.

$ exa -l --git
.rw-r--r--  11k user 10 Dec 18:26 -- Cargo.lock
[...]

src/options.rs

@@ -727,9 +727,8 @@ LONG VIEW OPTIONS
   -U, --created      display timestamp of creation for a file
 "##;
 
-static GIT_HELP:      &'static str = r##"  -@, --extended     display extended attribute keys and sizes"##;
-static EXTENDED_HELP: &'static str = r##"  --git              show git status for files"##;
-
+static GIT_HELP:      &'static str = r##"  --git              show git status for files"##;
+static EXTENDED_HELP: &'static str = r##"  -@, --extended     display extended attribute keys and sizes"##;
 
 #[cfg(test)]
 mod test {