httppeer: make sure we limit argument for older server not supporting batch

Most commands will still have some argument restriction when using 'GET' method
instead of batching through POST.

mercurial/httppeer.py

@@ -382,7 +382,9 b' class httppeer(wireprotov1peer.wirepeer)'
         self._path = path
         self._url = url
         self._caps = caps
-        self.limitedarguments = caps is not None and 'httppostargs' not in caps
+        self.limitedarguments = False
+        if caps is None or 'batch' not in caps or 'httppostargs' not in caps:
+            self.limitedarguments = True
         self._urlopener = opener
         self._requestbuilder = requestbuilder