largefile: use sysstr to check for attribute presence in `openstore`

We do not need bytes here.

hgext/largefiles/storefactory.py

@@ -57,7 +57,7 b' def openstore(repo=None, remote=None, pu'
 
     # The path could be a scheme so use Mercurial's normal functionality
     # to resolve the scheme to a repository and use its path
-    path = util.safehasattr(remote, b'url') and remote.url() or remote.path
+    path = util.safehasattr(remote, 'url') and remote.url() or remote.path
 
     match = _scheme_re.match(path)
     if not match:  # regular filesystem path