Firefox does not prompt for password for http authenticated sites, how to make it prompt?

NTLMv1 authentication has been disabled by default in Firefox 30. To enable, the pref network.negotiate-auth.allow-insecure-ntlm-v1 needs to be set to True. See: https://developer.mozilla.org/en-US/Firefox/Releases/30/Site_Compatibility (down the page under "Security").

I set: network.negotiate-auth.allow-insecure-ntlm-v1 to true

and now I am getting the prompts again.