problem with sudo apt-get update ubuntu 16.04

crazy@crazy:~$ sudo apt-get update
[sudo] password for crazy: 
Hit:1 http://dz.archive.ubuntu.com/ubuntu xenial InRelease                     
Hit:2 http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu xenial InRelease         
Get:3 http://dz.archive.ubuntu.com/ubuntu xenial-updates InRelease [93.3 kB]   
Get:4 http://security.ubuntu.com/ubuntu xenial-security InRelease [92.2 kB]  
Ign:5 http://dl.google.com/linux/talkplugin/deb stable InRelease                            
Hit:7 http://dz.archive.ubuntu.com/ubuntu xenial-backports InRelease                                       
Get:8 http://dz.archive.ubuntu.com/ubuntu xenial-proposed InRelease [247 kB]
Get:6 http://dl.google.com/linux/talkplugin/deb stable Release [1,347 B]
Get:9 http://dl.google.com/linux/talkplugin/deb stable Release.gpg [198 B]
Fetched 434 kB in 8s (52.2 kB/s)                                                                                                                
Reading package lists... Done
W: http://dl.google.com/linux/talkplugin/deb/dists/stable/Release.gpg: Signature by key 4CCA1EAF950CEE4AB83976DCA040830F71 uses weak digest algorithm (SHA1)
E: Failed to fetch http://dl.google.com/linux/talkplugin/deb/dists/stable/Release  No Hash entry in Release file /var/lib/apt/lists/partial/dl.google.com_linux_talkplugin_deb_dists_stable_Release which is considered strong enough for security purposes
E: Some index files failed to download. They have been ignored, or old ones used instead.
crazy@crazy:~$ 

how i can fix that ?