FoxyProxy package was renamed in Debian.

config/chroot_apt/preferences

@@ -10,10 +10,6 @@ Package: florence
 Pin: origin backports.debian.org
 Pin-Priority: 999
 
-Package: foxyproxy
-Pin: release o=Debian,a=unstable
-Pin-Priority: 999
-
 Package: haveged
 Pin: origin backports.debian.org
 Pin-Priority: 999
@@ -178,6 +174,10 @@ Package: xul-ext-cookie-monster
 Pin: release o=Debian,a=unstable
 Pin-Priority: 999
 
+Package: xul-ext-foxyproxy-standard
+Pin: release o=Debian,a=unstable
+Pin-Priority: 999
+
 Package: xul-ext-greasemonkey
 Pin: release o=Debian,a=unstable
 Pin-Priority: 999

config/chroot_local-packageslists/tails-common.list

@@ -59,7 +59,6 @@ evince
 exiv2
 file-roller
 florence
-foxyproxy
 gcalctool
 gedit
 gimp
@@ -166,6 +165,7 @@ wireless-tools
 xul-ext-adblock-plus
 xul-ext-cookie-monster
 xul-ext-firegpg
+xul-ext-foxyproxy-standard
 xul-ext-greasemonkey
 xul-ext-https-everywhere
 xul-ext-monkeysphere