Update debian install instructions, jessie-backports
diff --git a/INSTALL b/INSTALL
index de13d65..a0df57d 100644
--- a/INSTALL
+++ b/INSTALL
@@ -11,12 +11,12 @@
 
 On Linux (Debian):
 
- Note: you will need to add the Debian 'testing' distribution to your sources
+ Note: you will need to add the Debian 'jessie-backports' distribution to your sources
  file first.
 
  Add the following line to your `/etc/apt/sources.list` file:
 
-   deb http://ftp.us.debian.org/debian testing main contrib non-free
+   deb http://http.debian.net/debian jessie-backports main
 
  Install the gRPC library: