assure that whitespace can't be used to mask command-line arguments in file:// invocations

This also means that directory names can't start with a `-` out of principle, at least when
trying to locally fetch from them.

Author: Byron

gix-transport/src/client/blocking_io/file.rs

@@ -216,7 +216,7 @@ impl client::Transport for SpawnProcessOnDemand {
         };
         cmd.stdin = Stdio::piped();
         cmd.stdout = Stdio::piped();
-        if self.path.first() == Some(&b'-') {
+        if self.path.trim().first() == Some(&b'-') {
             return Err(client::Error::AmbiguousPath {
                 path: self.path.clone(),
             });