fix: trim whitespaces from token

Signed-off-by: German Lashevich <[email protected]>

pkg/vendir/fetch/githubrelease/sync.go

@@ -435,7 +435,7 @@ func (d Sync) authToken() (string, error) {
 		}
 	}
 
-	return token, nil
+	return strings.TrimSpace(token), nil
 }
 
 type ReleaseAPI struct {