[py] fix file uploads for Firefox

_is_remote needs to be set to False after calling RemoteWebDriver.__init__ since it sets it to True

Author: lmtierney

py/selenium/webdriver/firefox/webdriver.py

@@ -105,7 +105,6 @@ def __init__(self, firefox_profile=None, firefox_binary=None,
         self.profile = None
         self.service = None
         self._w3c = False
-        self._is_remote = False
 
         if capabilities is None:
             capabilities = DesiredCapabilities.FIREFOX.copy()
@@ -176,6 +175,8 @@ def __init__(self, firefox_profile=None, firefox_binary=None,
                 desired_capabilities=capabilities,
                 keep_alive=True)
 
+        self._is_remote = False
+
     def quit(self):
         """Quits the driver and close every associated window."""
         try: